Tutorial setup

If you have not done the prior sections, you’ll need to start the docker image:

docker run -it ghcr.io/spack/tutorial:isc23

and then set Spack up like this:

git clone --depth=100 --branch=releases/v0.20 https://github.com/spack/spack
. spack/share/spack/setup-env.sh
spack tutorial -y
spack bootstrap now
spack compiler find

See the Basic Installation Tutorial for full details on setup. For more help, join us in the #tutorial channel on Slack – get an invitation at slack.spack.io

Module Files Tutorial

This tutorial illustrates how Spack can be used to generate module files for the software that has been installed. Both hierarchical and non-hierarchical deployments will be discussed in details and we will show how to customize the content and naming of each module file.

At the end of the tutorial readers should have a clear understanding of:

  • What module files are and how they are used on HPC clusters
  • How Spack generates module files for the software it installs
  • Which Spack commands can be used to manage module files
  • How module files generated by Spack can be customized

and be confident that Spack can deal with all of the common use cases that occur when maintaining software installations on HPC clusters.

Setup for the Tutorial

To prepare for this tutorial we are going to install a small but representative set of software that includes different configurations of the same packages and some external packages. To keep the installations manageable, let’s start by uninstalling everything from earlier in the tutorial:

$ spack uninstall -ay

and by enabling tcl module files, which are disabled by default since Spack v0.20:

$ spack config add "modules:default:enable:[tcl]"

Build a module tool

The first thing that we need is the module tool itself. In the tutorial we will use lmod because it can work with both hierarchical and non-hierarchical layouts.

$ spack install lmod

Once the module tool is installed we need to have it available in the current shell. Installation directories in Spack’s store are definitely not easy to remember, but they can be retrieved with the spack location command:

$ . $(spack location -i lmod)/lmod/lmod/init/bash

Now we can re-source the setup file and Spack modules will be put in our module path.

$ . spack/share/spack/setup-env.sh

Add a new compiler

The second step is to build a recent compiler. On first use, Spack scans the environment and automatically locates the compiler(s) already available on the system. For this tutorial, however, we want to use gcc@12.1.0.

$ spack install gcc@12.1.0

You can get this in your environment using spack load gcc@12.1.0:

$ spack load gcc@12.1.0
$ which gcc
/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gcc

Now, gcc is in your PATH. You can add it to the list of compilers with spack compiler add:

$ spack compiler add
==> Added 1 new compiler to /home/spack/.spack/linux/compilers.yaml
    gcc@=12.1.0
==> Compilers are defined in the following files:
    /home/spack/.spack/linux/compilers.yaml

To check which compilers are available you can use spack compiler list:

$ spack compiler list
==> Available compilers
-- clang ubuntu22.04-x86_64 -------------------------------------
clang@=14.0.0

-- gcc ubuntu22.04-x86_64 ---------------------------------------
gcc@=12.1.0  gcc@=11.3.0  gcc@=10.4.0

Finally, when you confirmed gcc@12.1.0 is properly registered, clean the environment with spack unload:

$ spack unload --all

Build the software that will be used in the tutorial

Finally, we will use Spack to install the packages used in the examples:

$ spack install netlib-scalapack ^openmpi ^openblas
$ spack install netlib-scalapack ^mpich ^openblas
$ spack install netlib-scalapack ^openmpi ^netlib-lapack
$ spack install netlib-scalapack ^mpich ^netlib-lapack
$ spack install py-scipy ^openblas

What are Module Files?

Module files are an easy way to modify your environment in a controlled manner during a shell session. In general, they contain the information needed to run an application or use a library. The module command is used to interpret and execute module files. For example, module show tells you what a module will do when loaded:

spack@a7c82535d8c9:~$ module show zlib-1.2.13-gcc-11.3.0-mntflxr
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3/zlib-1.2.13-gcc-11.3.0-mntflxr:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
whatis("A free, general-purpose, legally unencumbered lossless data-compression library.")
prepend_path("MANPATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/zlib-1.2.13-mntflxrgekkm5lbpbl5r66lh2ieted4y/share/man")
prepend_path("PKG_CONFIG_PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/zlib-1.2.13-mntflxrgekkm5lbpbl5r66lh2ieted4y/lib/pkgconfig")
prepend_path("CMAKE_PREFIX_PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/zlib-1.2.13-mntflxrgekkm5lbpbl5r66lh2ieted4y/.")
help([[Name   : zlib
Version: 1.2.13
Target : x86_64_v3

A free, general-purpose, legally unencumbered lossless data-compression
module.
]])

$ echo $PKG_CONFIG_PATH

module load will execute all of the changes shown above:

spack@a7c82535d8c9:~$ module load gcc-12.1.0-gcc-11.3.0-s5e5zwr
spack@a7c82535d8c9:~$ echo $PKG_CONFIG_PATH
/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/zstd-1.5.5-qoo4rlopj4vqbc6k633cu3tzawtfjjvh/lib/pkgconfig:/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/zlib-1.2.13-mntflxrgekkm5lbpbl5r66lh2ieted4y/lib/pkgconfig:/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/mpfr-4.2.0-aiys7vci7zwuci5phi5yje7ql3des4jw/lib/pkgconfig:/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gmp-6.2.1-7kxi3rr3qduvmao43tjigamo2eqdme4q/lib/pkgconfig

and to undo the modifications, you can use module unload:

$ module unload zlib
$ echo $PKG_CONFIG_PATH

$

Module Systems

There are two main module systems used in HPC, both installable by Spack. In this tutorial we will be working with lmod and be showing examples with both Tcl and Lua.

Environment Modules

This is the original modules tool. It can be installed with Spack using the following command:

$ spack install environment-modules

It was first coded in C in the early 1990s and was later rewritten entirely in Tcl. Long stagnant, the project has been revived in the past few years by Xavier Delaruelle at CEA, and it is now very actively developed. For further details we refer to its documentation.

Lmod

Lmod is a module system written in Lua, originally created at the “Texas Advanced Computing Center” (TACC) by Robert McLay. You can get it with:

$ spack install lmod

as shown in the Setup for the Tutorial section. It is a drop-in replacement for Environment Modules, and it works with both Tcl and Lua module files. It is fully compatible with Environment Modules, but it also has many distinguishing features of its own. The main one is the module hierarchy, which simplifies the module UI by only showing modules built with the currently loaded compiler and/or MPI. There are also some unique safety features.

How does Spack generate module files?

Before we dive into the hands-on sections it’s worth explaining how module files are generated by Spack. The following diagram provides a high-level view of the process:

_images/module_file_generation.png

Modules in Spack are generated using configuration files (config.yaml and modules.yaml), information from Spack’s package recipes, and Jinja2 templates. Spack comes with Jinja2, an external template engine, so you do not need to install it yourself.

Modules vs spack load

You may have noticed that we used spack load in the Setup for the Tutorial section above. This is a built-in mechanism of Spack’s – it’s designed so that users on a cluster or a laptop can quickly get a package into their path, and it understands Spack’s spec syntax. It does not require modules, as Spack needs to work regardless of whether modules are set up on the system.

As you might expect, you can see what is loaded via spack load using spack find:

$ spack find --loaded
-- linux-ubuntu22.04-x86_64_v3 / gcc@=11.3.0 --------------------
autoconf@2.69		     automake@1.16.5	  bzip2@1.0.8	 gawk@5.2.1  gdbm@1.23	     gmake@4.4.1  libiconv@1.17    libtool@2.4.7   m4@1.4.19  mpfr@4.2.0   perl@5.36.0	pkgconf@1.9.5  tar@1.34       xz@5.4.1	   zstd@1.5.5
autoconf-archive@2023.02.20  berkeley-db@18.1.40  diffutils@3.9  gcc@12.1.0  gettext@0.21.1  gmp@6.2.1	  libsigsegv@2.14  libxml2@2.10.3  mpc@1.3.1  ncurses@6.4  pigz@2.7	readline@8.2   texinfo@7.0.3  zlib@1.2.13
==> 29 loaded packages

Because Spack is designed to be run on HPC systems, it also generates a module file for every installed package. This allows users unfamiliar with Spack’s interface to see things through the module system they’re used to. To see this, try:

$ module avail

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3 -------------------------------------------------------------------------------------------------------
   autoconf-2.69-gcc-11.3.0-t4nuen3			    curl-8.0.1-gcc-11.3.0-4cec7ab	 gmake-4.4.1-gcc-11.3.0-guaj3kb        lua-5.4.4-gcc-11.3.0-l5jkvce		     openssl-1.1.1t-gcc-11.3.0-w2by2b2	  texinfo-7.0.3-gcc-11.3.0-tcpqkls
   autoconf-archive-2023.02.20-gcc-11.3.0-5wwl7c6	    diffutils-3.9-gcc-11.3.0-zdl3dic	 gmp-6.2.1-gcc-11.3.0-7kxi3rr	       lua-luafilesystem-1_8_0-gcc-11.3.0-23tvtrc    perl-5.36.0-gcc-11.3.0-j5tavds	  unzip-6.0-gcc-11.3.0-ttovk4w
   automake-1.16.5-gcc-11.3.0-oa3w4kf			    ed-1.4-gcc-11.3.0-yru5brp		 libiconv-1.17-gcc-11.3.0-7wr75ce      lua-luaposix-36.1-gcc-11.3.0-zebno4c	     pigz-2.7-gcc-11.3.0-aln73eo	  xz-5.4.1-gcc-11.3.0-4kpkw5a
   bc-1.07.1-gcc-11.3.0-ekfwavo 			    gawk-5.2.1-gcc-11.3.0-6lk2khk	 libsigsegv-2.14-gcc-11.3.0-okig24f    m4-1.4.19-gcc-11.3.0-llbjfk2		     pkgconf-1.9.5-gcc-11.3.0-mh73nkp	  zlib-1.2.13-gcc-11.3.0-mntflxr
   berkeley-db-18.1.40-gcc-11.3.0-7sohpaz		    gcc-12.1.0-gcc-11.3.0-s5e5zwr	 libtool-2.4.7-gcc-11.3.0-qkvj7am      mpc-1.3.1-gcc-11.3.0-3qvnliw		     readline-8.2-gcc-11.3.0-tddm2ff	  zstd-1.5.5-gcc-11.3.0-qoo4rlo
   bzip2-1.0.8-gcc-11.3.0-dca2qyg			    gdbm-1.23-gcc-11.3.0-ba4juc3	 libxml2-2.10.3-gcc-11.3.0-pcbenki     mpfr-4.2.0-gcc-11.3.0-aiys7vc		     tar-1.34-gcc-11.3.0-e77cf6a
   ca-certificates-mozilla-2023-01-10-gcc-11.3.0-5pxkrf4    gettext-0.21.1-gcc-11.3.0-p4obvgx	 lmod-8.7.24-gcc-11.3.0-hrwwlqa        ncurses-6.4-gcc-11.3.0-4dokmxj		     tcl-8.6.12-gcc-11.3.0-6afnoet

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

You can module load any of these. By default, Spack generates modules named by package-version-compiler-version-hash, which is a bit hard to read. We’ll show you how to customize this in the following sections.

Non-hierarchical Module Files

If you arrived to this point you should have an environment that looks similar to:

$ module avail

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3 -------------------------------------------------------------------------------------------------------
   autoconf-2.69-gcc-11.3.0-t4nuen3			    gdbm-1.23-gcc-12.1.0-febzyvz	       libxml2-2.10.3-gcc-12.1.0-sbbiixp	     openssl-1.1.1t-gcc-11.3.0-w2by2b2		       py-scipy-1.10.1-gcc-12.1.0-ol3w546
   autoconf-2.69-gcc-12.1.0-mr5osqp			    gettext-0.21.1-gcc-11.3.0-p4obvgx	       lmod-8.7.24-gcc-11.3.0-hrwwlqa		     openssl-1.1.1t-gcc-12.1.0-7dyvgor		       py-setuptools-63.4.3-gcc-12.1.0-wujb6fw
   autoconf-archive-2023.02.20-gcc-11.3.0-5wwl7c6	    gettext-0.21.1-gcc-12.1.0-7qnn3pi	       lua-5.4.4-gcc-11.3.0-l5jkvce		     perl-5.36.0-gcc-11.3.0-j5tavds		       py-tomli-2.0.1-gcc-12.1.0-ivq3gn7
   automake-1.16.5-gcc-11.3.0-oa3w4kf			    gmake-4.4.1-gcc-11.3.0-guaj3kb	       lua-luafilesystem-1_8_0-gcc-11.3.0-23tvtrc    perl-5.36.0-gcc-12.1.0-fq7gb4a		       py-wheel-0.37.1-gcc-12.1.0-kbelzwq
   automake-1.16.5-gcc-12.1.0-yyzuikk			    gmake-4.4.1-gcc-12.1.0-74omm4b	       lua-luaposix-36.1-gcc-11.3.0-zebno4c	     pigz-2.7-gcc-11.3.0-aln73eo		       python-3.10.10-gcc-12.1.0-nvcwpz4
   bc-1.07.1-gcc-11.3.0-ekfwavo 			    gmp-6.2.1-gcc-11.3.0-7kxi3rr	       m4-1.4.19-gcc-11.3.0-llbjfk2		     pigz-2.7-gcc-12.1.0-i2azy7n		       re2c-2.2-gcc-12.1.0-622aruu
   berkeley-db-18.1.40-gcc-11.3.0-7sohpaz		    hwloc-2.9.1-gcc-12.1.0-sd6g5bq	       m4-1.4.19-gcc-12.1.0-s6ky5ld		     pkgconf-1.9.5-gcc-11.3.0-mh73nkp		       readline-8.2-gcc-11.3.0-tddm2ff
   berkeley-db-18.1.40-gcc-12.1.0-vtjcxzc		    krb5-1.20.1-gcc-12.1.0-n5v3tug	       meson-1.1.0-gcc-12.1.0-s5rzrue		     pkgconf-1.9.5-gcc-12.1.0-gbfssja		       readline-8.2-gcc-12.1.0-qypmr5g
   bison-3.8.2-gcc-12.1.0-fjc7p57			    libbsd-0.11.7-gcc-12.1.0-kqphoxb	       mpc-1.3.1-gcc-11.3.0-3qvnliw		     pmix-4.2.3-gcc-12.1.0-ouqw26w		       sqlite-3.40.1-gcc-12.1.0-at2vwsu
   bzip2-1.0.8-gcc-11.3.0-dca2qyg			    libedit-3.1-20210216-gcc-12.1.0-xkjcqre    mpfr-4.2.0-gcc-11.3.0-aiys7vc		     py-beniget-0.4.1-gcc-12.1.0-s6swsfi	       tar-1.34-gcc-11.3.0-e77cf6a
   bzip2-1.0.8-gcc-12.1.0-ecute7q			    libevent-2.1.12-gcc-12.1.0-2y2whk4	       mpich-4.1.1-gcc-12.1.0-fb4tt65		     py-build-0.10.0-gcc-12.1.0-uhboysx 	       tar-1.34-gcc-12.1.0-2r7rutu
   ca-certificates-mozilla-2023-01-10-gcc-11.3.0-5pxkrf4    libfabric-1.18.0-gcc-12.1.0-er4rpyd        ncurses-6.4-gcc-11.3.0-4dokmxj		     py-cython-0.29.33-gcc-12.1.0-ny2lq6w	       tcl-8.6.12-gcc-11.3.0-6afnoet
   ca-certificates-mozilla-2023-01-10-gcc-12.1.0-7u553me    libffi-3.4.4-gcc-12.1.0-u2ztzc2	       ncurses-6.4-gcc-12.1.0-yugzpgp		     py-flit-core-3.7.1-gcc-12.1.0-ihmiu27	       texinfo-7.0.3-gcc-11.3.0-tcpqkls
   cmake-3.26.3-gcc-12.1.0-cb3vkyk			    libiconv-1.17-gcc-11.3.0-7wr75ce	       netlib-lapack-3.11.0-gcc-12.1.0-fjlwowf	     py-gast-0.5.3-gcc-12.1.0-xg26gxl		       unzip-6.0-gcc-11.3.0-ttovk4w
   curl-8.0.1-gcc-11.3.0-4cec7ab			    libiconv-1.17-gcc-12.1.0-ojujfjj	       netlib-scalapack-2.2.0-gcc-12.1.0-75u5574     py-meson-python-0.12.0-gcc-12.1.0-rosemhn	       util-linux-uuid-2.38.1-gcc-12.1.0-gbfbnoj
   diffutils-3.9-gcc-11.3.0-zdl3dic			    libmd-1.0.4-gcc-12.1.0-a4ofctm	       netlib-scalapack-2.2.0-gcc-12.1.0-ea7dxfb     py-numpy-1.24.3-gcc-12.1.0-54s3ofo 	       util-macros-1.19.3-gcc-12.1.0-imbmumc
   diffutils-3.9-gcc-12.1.0-csiltjm			    libpciaccess-0.17-gcc-12.1.0-4voenez       netlib-scalapack-2.2.0-gcc-12.1.0-qmna5re     py-packaging-23.0-gcc-12.1.0-yoamuqz	       xz-5.4.1-gcc-11.3.0-4kpkw5a
   ed-1.4-gcc-11.3.0-yru5brp				    libsigsegv-2.14-gcc-11.3.0-okig24f	       netlib-scalapack-2.2.0-gcc-12.1.0-yq5hsff     py-pip-23.0-gcc-12.1.0-khveatv		       xz-5.4.1-gcc-12.1.0-dat54qr
   expat-2.5.0-gcc-12.1.0-upevc4c			    libsigsegv-2.14-gcc-12.1.0-oyzxg5g	       ninja-1.11.1-gcc-12.1.0-2zgsglc		     py-ply-3.11-gcc-12.1.0-ovxjh5h		       yaksa-0.2-gcc-12.1.0-5mplopl
   findutils-4.9.0-gcc-12.1.0-hgvmfon			    libtool-2.4.7-gcc-11.3.0-qkvj7am	       numactl-2.0.14-gcc-12.1.0-45xq3wr	     py-pybind11-2.10.1-gcc-12.1.0-2hmi7rq	       zlib-1.2.13-gcc-11.3.0-mntflxr
   gawk-5.2.1-gcc-11.3.0-6lk2khk			    libtool-2.4.7-gcc-12.1.0-owrdqyk	       openblas-0.3.23-gcc-12.1.0-5hvwk3g	     py-pyproject-hooks-1.0.0-gcc-12.1.0-udgbusq       zlib-1.2.13-gcc-12.1.0-oboyaa5
   gcc-12.1.0-gcc-11.3.0-s5e5zwr			    libxcrypt-4.4.33-gcc-12.1.0-uq4wpnl        openmpi-4.1.5-gcc-12.1.0-ekmi64f 	     py-pyproject-metadata-0.7.1-gcc-12.1.0-lrhcey2    zstd-1.5.5-gcc-11.3.0-qoo4rlo
   gdbm-1.23-gcc-11.3.0-ba4juc3 			    libxml2-2.10.3-gcc-11.3.0-pcbenki	       openssh-9.3p1-gcc-12.1.0-vu4ehmb 	     py-pythran-0.12.0-gcc-12.1.0-s6iwj3a	       zstd-1.5.5-gcc-12.1.0-a5p5yob

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

The non-hierarchical module files that have been generated so far follow Spack’s default rules for module generation. Taking a look at the gcc module you’ll see, for example:

$ module show gcc-12.1.0-gcc-11.3.0-s5e5zwr
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0-gcc-11.3.0-s5e5zwr:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
whatis("The GNU Compiler Collection includes front ends for C, C++, Objective-C, Fortran, Ada, and Go, as well as libraries for these languages.")
load("gmp-6.2.1-gcc-11.3.0-7kxi3rr")
load("mpc-1.3.1-gcc-11.3.0-3qvnliw")
load("mpfr-4.2.0-gcc-11.3.0-aiys7vc")
load("zlib-1.2.13-gcc-11.3.0-mntflxr")
load("zstd-1.5.5-gcc-11.3.0-qoo4rlo")
prepend_path("PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin")
prepend_path("MANPATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/share/man")
prepend_path("CMAKE_PREFIX_PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/.")
setenv("CC","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gcc")
setenv("CXX","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/g++")
setenv("FC","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gfortran")
setenv("F77","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gfortran")
help([[Name   : gcc
Version: 12.1.0
Target : x86_64_v3

The GNU Compiler Collection includes front ends for C, C++, Objective-C,
Fortran, Ada, and Go, as well as libraries for these languages.
]])

As expected, a few environment variables representing paths will be modified by the module file according to the default prefix inspection rules.

Filter unwanted modifications to the environment

Now consider the case that your site has decided that CC, CXX, FC and F77 modifications should not be present in module files. What you can do to abide by the rules is to create a configuration file ${SPACK_ROOT}/etc/spack/modules.yaml with the following content:

modules:
  default:
    tcl:
      all:
        filter:
          exclude_env_vars:
          - "CC"
          - "CXX"
          - "FC"
          - "F77"

Next you should regenerate all the module files:

$ spack module tcl refresh -y
==> Regenerating tcl module files

If you take a look now at the module for gcc you’ll see that the unwanted paths have disappeared:

$ module show gcc-12.1.0-gcc-11.3.0-s5e5zwr
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0-gcc-11.3.0-s5e5zwr:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
whatis("The GNU Compiler Collection includes front ends for C, C++, Objective-C, Fortran, Ada, and Go, as well as libraries for these languages.")
load("gmp-6.2.1-gcc-11.3.0-7kxi3rr")
load("mpc-1.3.1-gcc-11.3.0-3qvnliw")
load("mpfr-4.2.0-gcc-11.3.0-aiys7vc")
load("zlib-1.2.13-gcc-11.3.0-mntflxr")
load("zstd-1.5.5-gcc-11.3.0-qoo4rlo")
prepend_path("PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin")
prepend_path("MANPATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/share/man")
prepend_path("CMAKE_PREFIX_PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/.")
setenv("CC","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gcc")
setenv("CXX","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/g++")
setenv("FC","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gfortran")
setenv("F77","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gfortran")
help([[Name   : gcc
Version: 12.1.0
Target : x86_64_v3

The GNU Compiler Collection includes front ends for C, C++, Objective-C,
Fortran, Ada, and Go, as well as libraries for these languages.
]])

Prevent some module files from being generated

Another common request at many sites is to avoid exposing software that is only needed as an intermediate step when building a newer stack. Let’s try to prevent the generation of module files for anything that is compiled with gcc@11.3.0 (the OS provided compiler).

To do this you should add the exclude keyword to ${SPACK_ROOT}/etc/spack/modules.yaml:

modules:
  default:
    tcl:
      exclude:
      -  '%gcc@11.3.0'
      all:
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"

and regenerate the module files. This time we’ll pass the option --delete-tree so that Spack will delete the existing module tree and regenerate a new one, instead of overwriting the files in the existing directory.

$ spack module tcl refresh --delete-tree -y
==> Regenerating tcl module files
$ module avail

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3 -------------------------------------------------------------------------------------------------------
   autoconf-2.69-gcc-12.1.0-mr5osqp			    libbsd-0.11.7-gcc-12.1.0-kqphoxb	       ncurses-6.4-gcc-12.1.0-yugzpgp		    pmix-4.2.3-gcc-12.1.0-ouqw26w		      py-scipy-1.10.1-gcc-12.1.0-ol3w546
   automake-1.16.5-gcc-12.1.0-yyzuikk			    libedit-3.1-20210216-gcc-12.1.0-xkjcqre    netlib-lapack-3.11.0-gcc-12.1.0-fjlwowf	    py-beniget-0.4.1-gcc-12.1.0-s6swsfi 	      py-setuptools-63.4.3-gcc-12.1.0-wujb6fw
   berkeley-db-18.1.40-gcc-12.1.0-vtjcxzc		    libevent-2.1.12-gcc-12.1.0-2y2whk4	       netlib-scalapack-2.2.0-gcc-12.1.0-75u5574    py-build-0.10.0-gcc-12.1.0-uhboysx		      py-tomli-2.0.1-gcc-12.1.0-ivq3gn7
   bison-3.8.2-gcc-12.1.0-fjc7p57			    libfabric-1.18.0-gcc-12.1.0-er4rpyd        netlib-scalapack-2.2.0-gcc-12.1.0-ea7dxfb    py-cython-0.29.33-gcc-12.1.0-ny2lq6w	      py-wheel-0.37.1-gcc-12.1.0-kbelzwq
   bzip2-1.0.8-gcc-12.1.0-ecute7q			    libffi-3.4.4-gcc-12.1.0-u2ztzc2	       netlib-scalapack-2.2.0-gcc-12.1.0-qmna5re    py-flit-core-3.7.1-gcc-12.1.0-ihmiu27	      python-3.10.10-gcc-12.1.0-nvcwpz4
   ca-certificates-mozilla-2023-01-10-gcc-12.1.0-7u553me    libiconv-1.17-gcc-12.1.0-ojujfjj	       netlib-scalapack-2.2.0-gcc-12.1.0-yq5hsff    py-gast-0.5.3-gcc-12.1.0-xg26gxl		      re2c-2.2-gcc-12.1.0-622aruu
   cmake-3.26.3-gcc-12.1.0-cb3vkyk			    libmd-1.0.4-gcc-12.1.0-a4ofctm	       ninja-1.11.1-gcc-12.1.0-2zgsglc		    py-meson-python-0.12.0-gcc-12.1.0-rosemhn	      readline-8.2-gcc-12.1.0-qypmr5g
   diffutils-3.9-gcc-12.1.0-csiltjm			    libpciaccess-0.17-gcc-12.1.0-4voenez       numactl-2.0.14-gcc-12.1.0-45xq3wr	    py-numpy-1.24.3-gcc-12.1.0-54s3ofo		      sqlite-3.40.1-gcc-12.1.0-at2vwsu
   expat-2.5.0-gcc-12.1.0-upevc4c			    libsigsegv-2.14-gcc-12.1.0-oyzxg5g	       openblas-0.3.23-gcc-12.1.0-5hvwk3g	    py-packaging-23.0-gcc-12.1.0-yoamuqz	      tar-1.34-gcc-12.1.0-2r7rutu
   findutils-4.9.0-gcc-12.1.0-hgvmfon			    libtool-2.4.7-gcc-12.1.0-owrdqyk	       openmpi-4.1.5-gcc-12.1.0-ekmi64f 	    py-pip-23.0-gcc-12.1.0-khveatv		      util-linux-uuid-2.38.1-gcc-12.1.0-gbfbnoj
   gdbm-1.23-gcc-12.1.0-febzyvz 			    libxcrypt-4.4.33-gcc-12.1.0-uq4wpnl        openssh-9.3p1-gcc-12.1.0-vu4ehmb 	    py-ply-3.11-gcc-12.1.0-ovxjh5h		      util-macros-1.19.3-gcc-12.1.0-imbmumc
   gettext-0.21.1-gcc-12.1.0-7qnn3pi			    libxml2-2.10.3-gcc-12.1.0-sbbiixp	       openssl-1.1.1t-gcc-12.1.0-7dyvgor	    py-pybind11-2.10.1-gcc-12.1.0-2hmi7rq	      xz-5.4.1-gcc-12.1.0-dat54qr
   gmake-4.4.1-gcc-12.1.0-74omm4b			    m4-1.4.19-gcc-12.1.0-s6ky5ld	       perl-5.36.0-gcc-12.1.0-fq7gb4a		    py-pyproject-hooks-1.0.0-gcc-12.1.0-udgbusq       yaksa-0.2-gcc-12.1.0-5mplopl
   hwloc-2.9.1-gcc-12.1.0-sd6g5bq			    meson-1.1.0-gcc-12.1.0-s5rzrue	       pigz-2.7-gcc-12.1.0-i2azy7n		    py-pyproject-metadata-0.7.1-gcc-12.1.0-lrhcey2    zlib-1.2.13-gcc-12.1.0-oboyaa5
   krb5-1.20.1-gcc-12.1.0-n5v3tug			    mpich-4.1.1-gcc-12.1.0-fb4tt65	       pkgconf-1.9.5-gcc-12.1.0-gbfssja 	    py-pythran-0.12.0-gcc-12.1.0-s6iwj3a	      zstd-1.5.5-gcc-12.1.0-a5p5yob

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

if you look closely you’ll see though that we went too far in excluding modules: the module for gcc@12.1.0 disappeared as it was bootstrapped with gcc@11.3.0. To specify exceptions to the exclude rules you can use include:

modules:
  default:
    tcl:
      include:
      -  gcc
      exclude:
      -  '%gcc@11.3.0'
      all:
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"

include rules always have precedence over exclude rules. If you regenerate the modules again:

$ spack module tcl refresh -y
==> Regenerating tcl module files

you’ll see that now the module for gcc@12.1.0 has reappeared:

$ module avail gcc-12.1.0-gcc-11.3.0-s5e5zwr

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3 -------------------------------------------------------------------------------------------------------
   gcc-12.1.0-gcc-11.3.0-s5e5zwr

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

An additional feature that you can leverage to unclutter the environment is to skip the generation of module files for implicitly installed packages. In this case you only need to add the following line:

modules:
  default:
    tcl:
      exclude_implicits: true
      include:
      -  gcc
      exclude:
      -  '%gcc@11.3.0'
      all:
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"

to modules.yaml and regenerate the module file tree as above.

Change module file naming

The next step in making module files more user-friendly is to improve their naming scheme. To reduce the length of the hash or remove it altogether you can use the hash_length keyword in the configuration file:

modules:
  default:
    tcl:
      hash_length: 0
      include:
      -  gcc
      exclude:
      -  '%gcc@11.3.0'
      all:
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"

If you try to regenerate the module files now you will get an error:

$ spack module tcl refresh --delete-tree -y
==> Error: Name clashes detected in module files:

file: /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3/netlib-scalapack-2.2.0-gcc-12.1.0
spec: netlib-scalapack@=2.2.0%gcc@=12.1.0~ipo~pic+shared build_system=cmake build_type=Release generator=make patches=072b006,1c9ce5f,244a9aa arch=linux-ubuntu22.04-x86_64_v3
spec: netlib-scalapack@=2.2.0%gcc@=12.1.0~ipo~pic+shared build_system=cmake build_type=Release generator=make patches=072b006,1c9ce5f,244a9aa arch=linux-ubuntu22.04-x86_64_v3
spec: netlib-scalapack@=2.2.0%gcc@=12.1.0~ipo~pic+shared build_system=cmake build_type=Release generator=make patches=072b006,1c9ce5f,244a9aa arch=linux-ubuntu22.04-x86_64_v3
spec: netlib-scalapack@=2.2.0%gcc@=12.1.0~ipo~pic+shared build_system=cmake build_type=Release generator=make patches=072b006,1c9ce5f,244a9aa arch=linux-ubuntu22.04-x86_64_v3

==> Error: Operation aborted

Note

We try to check for errors up front!

In Spack we check for errors upfront whenever possible, so don’t worry about your module files: as a name clash was detected nothing has been changed on disk.

The problem here is that without the hashes the four different flavors of netlib-scalapack map to the same module file name. We can change how the names are formatted to differentiate them:

modules:
  default:
    tcl:
      hash_length: 0
      include:
      -  gcc
      exclude:
      -  '%gcc@11.3.0'
      all:
        conflict:
        - '{name}'
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"
      projections:
        all:               '{name}/{version}-{compiler.name}-{compiler.version}'
        netlib-scalapack:  '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}-{^mpi.name}'
        ^python^lapack:    '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}'

As you can see it is possible to specify rules that apply only to a restricted set of packages using anonymous specs like ^mpi^lapack. Here we declare a conflict between any two modules with the same name, so they cannot be loaded together. We also format the names of modules according to compiler, compiler version, and MPI version using the spec format syntax. This allows us to match specs by their dependencies, and format them based on their DAGs.

$ spack module tcl refresh --delete-tree -y
==> Regenerating tcl module files
$ module avail

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3 -------------------------------------------------------------------------------------------------------
   autoconf/2.69-gcc-12.1.0			    gmake/4.4.1-gcc-12.1.0	       libxcrypt/4.4.33-gcc-12.1.0				      openblas/0.3.23-gcc-12.1.0       py-meson-python/0.12.0-gcc-12.1.0	 python/3.10.10-gcc-12.1.0
   automake/1.16.5-gcc-12.1.0			    hwloc/2.9.1-gcc-12.1.0	       libxml2/2.10.3-gcc-12.1.0				      openmpi/4.1.5-gcc-12.1.0	       py-numpy/1.24.3-gcc-12.1.0-openblas	 re2c/2.2-gcc-12.1.0
   berkeley-db/18.1.40-gcc-12.1.0		    krb5/1.20.1-gcc-12.1.0	       m4/1.4.19-gcc-12.1.0					      openssh/9.3p1-gcc-12.1.0	       py-packaging/23.0-gcc-12.1.0		 readline/8.2-gcc-12.1.0
   bison/3.8.2-gcc-12.1.0			    libbsd/0.11.7-gcc-12.1.0	       meson/1.1.0-gcc-12.1.0					      openssl/1.1.1t-gcc-12.1.0        py-pip/23.0-gcc-12.1.0			 sqlite/3.40.1-gcc-12.1.0
   bzip2/1.0.8-gcc-12.1.0			    libedit/3.1-20210216-gcc-12.1.0    mpich/4.1.1-gcc-12.1.0					      perl/5.36.0-gcc-12.1.0	       py-ply/3.11-gcc-12.1.0			 tar/1.34-gcc-12.1.0
   ca-certificates-mozilla/2023-01-10-gcc-12.1.0    libevent/2.1.12-gcc-12.1.0	       ncurses/6.4-gcc-12.1.0					      pigz/2.7-gcc-12.1.0	       py-pybind11/2.10.1-gcc-12.1.0		 util-linux-uuid/2.38.1-gcc-12.1.0
   cmake/3.26.3-gcc-12.1.0			    libfabric/1.18.0-gcc-12.1.0        netlib-lapack/3.11.0-gcc-12.1.0				      pkgconf/1.9.5-gcc-12.1.0	       py-pyproject-hooks/1.0.0-gcc-12.1.0	 util-macros/1.19.3-gcc-12.1.0
   diffutils/3.9-gcc-12.1.0			    libffi/3.4.4-gcc-12.1.0	       netlib-scalapack/2.2.0-gcc-12.1.0-netlib-lapack-mpich	      pmix/4.2.3-gcc-12.1.0	       py-pyproject-metadata/0.7.1-gcc-12.1.0	 xz/5.4.1-gcc-12.1.0
   expat/2.5.0-gcc-12.1.0			    libiconv/1.17-gcc-12.1.0	       netlib-scalapack/2.2.0-gcc-12.1.0-netlib-lapack-openmpi	      py-beniget/0.4.1-gcc-12.1.0      py-pythran/0.12.0-gcc-12.1.0-openblas	 yaksa/0.2-gcc-12.1.0
   findutils/4.9.0-gcc-12.1.0			    libmd/1.0.4-gcc-12.1.0	       netlib-scalapack/2.2.0-gcc-12.1.0-openblas-mpich 	      py-build/0.10.0-gcc-12.1.0       py-scipy/1.10.1-gcc-12.1.0-openblas	 zlib/1.2.13-gcc-12.1.0
   gcc/12.1.0-gcc-11.3.0			    libpciaccess/0.17-gcc-12.1.0       netlib-scalapack/2.2.0-gcc-12.1.0-openblas-openmpi      (D)    py-cython/0.29.33-gcc-12.1.0     py-setuptools/63.4.3-gcc-12.1.0		 zstd/1.5.5-gcc-12.1.0
   gdbm/1.23-gcc-12.1.0 			    libsigsegv/2.14-gcc-12.1.0	       ninja/1.11.1-gcc-12.1.0					      py-flit-core/3.7.1-gcc-12.1.0    py-tomli/2.0.1-gcc-12.1.0
   gettext/0.21.1-gcc-12.1.0			    libtool/2.4.7-gcc-12.1.0	       numactl/2.0.14-gcc-12.1.0				      py-gast/0.5.3-gcc-12.1.0	       py-wheel/0.37.1-gcc-12.1.0

  Where:
   D:  Default Module

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

Note

The conflict directive is Tcl-specific and can’t be used in the lmod section of the configuration file.

Add custom environment modifications

At many sites it is customary to set an environment variable in a package’s module file that points to the folder in which the package is installed. You can achieve this with Spack by adding an environment directive to the configuration file:

modules:
  default:
    tcl:
      hash_length: 0
      naming_scheme: '{name}/{version}-{compiler.name}-{compiler.version}'
      include:
      -  gcc
      exclude:
      -  '%gcc@11.3.0'
      all:
        conflict:
        - '{name}'
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"
        environment:
          set:
            '{name}_ROOT': '{prefix}'
      projections:
        all:               '{name}/{version}-{compiler.name}-{compiler.version}'
        netlib-scalapack:  '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}-{^mpi.name}'
        ^python^lapack:    '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}'

Under the hood Spack uses the format() API to substitute tokens in either environment variable names or values. There are two caveats though:

  • The set of allowed tokens in variable names is restricted to name, version, compiler, compiler.name, compiler.version, architecture
  • Any token expanded in a variable name is made uppercase, but other than that case sensitivity is preserved

Regenerating the module files results in something like:

$ spack module tcl refresh -y
==> Regenerating tcl module files
$ module show gcc
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3/gcc/12.1.0-gcc-11.3.0:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
whatis("The GNU Compiler Collection includes front ends for C, C++, Objective-C, Fortran, Ada, and Go, as well as libraries for these languages.")
conflict("gcc")
prepend_path("PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin")
prepend_path("MANPATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/share/man")
prepend_path("CMAKE_PREFIX_PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/.")
setenv("CC","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gcc")
setenv("CXX","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/g++")
setenv("FC","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gfortran")
setenv("F77","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx/bin/gfortran")
setenv("GCC_ROOT","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-11.3.0/gcc-12.1.0-s5e5zwrzqozb5e6liaz3tjm6achptgzx")
help([[Name   : gcc
Version: 12.1.0
Target : x86_64_v3

The GNU Compiler Collection includes front ends for C, C++, Objective-C,
Fortran, Ada, and Go, as well as libraries for these languages.
]])

As you can see, the gcc module has the environment variable GCC_ROOT set.

Sometimes it’s also useful to apply environment modifications selectively and target only certain packages. You can for instance apply modifications to the openmpi module as follows:

modules:
  default:
    tcl:
      hash_length: 0
      naming_scheme: '{name}/{version}-{compiler.name}-{compiler.version}'
      include:
      - gcc
      exclude:
      - '%gcc@11.3.0'
      all:
        conflict:
        - '{name}'
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"
        environment:
          set:
            '{name}_ROOT': '{prefix}'
      openmpi:
        environment:
          set:
            SLURM_MPI_TYPE: pmi2
            OMPI_MCA_btl_openib_warn_default_gid_prefix: '0'
      projections:
        all:               '{name}/{version}-{compiler.name}-{compiler.version}'
        netlib-scalapack:  '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}-{^mpi.name}'
        ^python^lapack:    '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}'

This time we will be more selective and regenerate only the openmpi module file:

$ spack module tcl refresh -y openmpi
==> Regenerating tcl module files
$ module show openmpi
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3/openmpi/4.1.5-gcc-12.1.0:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
whatis("An open source Message Passing Interface implementation.")
load("hwloc/2.9.1-gcc-12.1.0")
load("numactl/2.0.14-gcc-12.1.0")
load("openssh/9.3p1-gcc-12.1.0")
load("pmix/4.2.3-gcc-12.1.0")
load("zlib/1.2.13-gcc-12.1.0")
conflict("openmpi")
prepend_path("PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/bin")
prepend_path("MANPATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/share/man")
prepend_path("PKG_CONFIG_PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/lib/pkgconfig")
prepend_path("CMAKE_PREFIX_PATH","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/.")
setenv("MPICC","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/bin/mpicc")
setenv("MPICXX","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/bin/mpic++")
setenv("MPIF77","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/bin/mpif77")
setenv("MPIF90","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx/bin/mpif90")
setenv("OPENMPI_ROOT","/home/spack/spack/opt/spack/linux-ubuntu22.04-x86_64_v3/gcc-12.1.0/openmpi-4.1.5-ekmi64fdx3jcorwo3irbmlxza6f4atkx")
setenv("SLURM_MPI_TYPE","pmi2")
setenv("OMPI_MCA_btl_openib_warn_default_git_prefix","0")
help([[Name   : openmpi
Version: 4.1.5
Target : x86_64_v3

An open source Message Passing Interface implementation. The Open MPI
Project is an open source Message Passing Interface implementation that
is developed and maintained by a consortium of academic, research, and
industry partners. Open MPI is therefore able to combine the expertise,
technologies, and resources from all across the High Performance
Computing community in order to build the best MPI library available.
Open MPI offers advantages for system and software vendors, application
developers and computer science researchers.
]])

Autoload dependencies

Spack can also generate module files that contain code to load the dependencies automatically. You can, for instance generate python modules that load their dependencies by adding the autoload directive and assigning it the value direct:

modules:
  default:
    tcl:
      verbose: True
      hash_length: 0
      naming_scheme: '{name}/{version}-{compiler.name}-{compiler.version}'
      include:
      - gcc
      exclude:
      - '%gcc@11.3.0'
      all:
        conflict:
        - '{name}'
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"
        environment:
          set:
            '{name}_ROOT': '{prefix}'
      gcc:
        environment:
          set:
            CC: gcc
            CXX: g++
            FC: gfortran
            F90: gfortran
            F77: gfortran
      openmpi:
        environment:
          set:
            SLURM_MPI_TYPE: pmi2
            OMPI_MCA_btl_openib_warn_default_gid_prefix: '0'
      projections:
        all:               '{name}/{version}-{compiler.name}-{compiler.version}'
        netlib-scalapack:  '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}-{^mpi.name}'
        ^python^lapack:    '{name}/{version}-{compiler.name}-{compiler.version}-{^lapack.name}'
      ^python:
        autoload:  direct

and regenerating the module files for every package that depends on python:

$ spack module tcl refresh -y ^python
==> Regenerating tcl module files

and will contain code to autoload all the dependencies:

$ module load py-scipy

In case messages are unwanted during the autoload procedure, it will be sufficient to omit the line setting verbose: True in the configuration file above.

Hierarchical Module Files

So far we worked with non-hierarchical module files, i.e. with module files that are all generated in the same root directory and don’t attempt to dynamically modify the MODULEPATH. This results in a flat module structure where all the software is visible at the same time:

$ module avail

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/modules/linux-ubuntu22.04-x86_64_v3 -------------------------------------------------------------------------------------------------------
   autoconf/2.69-gcc-12.1.0			    gmake/4.4.1-gcc-12.1.0	       libxcrypt/4.4.33-gcc-12.1.0				      openblas/0.3.23-gcc-12.1.0       py-meson-python/0.12.0-gcc-12.1.0	 python/3.10.10-gcc-12.1.0
   automake/1.16.5-gcc-12.1.0			    hwloc/2.9.1-gcc-12.1.0	       libxml2/2.10.3-gcc-12.1.0				      openmpi/4.1.5-gcc-12.1.0	       py-numpy/1.24.3-gcc-12.1.0-openblas	 re2c/2.2-gcc-12.1.0
   berkeley-db/18.1.40-gcc-12.1.0		    krb5/1.20.1-gcc-12.1.0	       m4/1.4.19-gcc-12.1.0					      openssh/9.3p1-gcc-12.1.0	       py-packaging/23.0-gcc-12.1.0		 readline/8.2-gcc-12.1.0
   bison/3.8.2-gcc-12.1.0			    libbsd/0.11.7-gcc-12.1.0	       meson/1.1.0-gcc-12.1.0					      openssl/1.1.1t-gcc-12.1.0        py-pip/23.0-gcc-12.1.0			 sqlite/3.40.1-gcc-12.1.0
   bzip2/1.0.8-gcc-12.1.0			    libedit/3.1-20210216-gcc-12.1.0    mpich/4.1.1-gcc-12.1.0					      perl/5.36.0-gcc-12.1.0	       py-ply/3.11-gcc-12.1.0			 tar/1.34-gcc-12.1.0
   ca-certificates-mozilla/2023-01-10-gcc-12.1.0    libevent/2.1.12-gcc-12.1.0	       ncurses/6.4-gcc-12.1.0					      pigz/2.7-gcc-12.1.0	       py-pybind11/2.10.1-gcc-12.1.0		 util-linux-uuid/2.38.1-gcc-12.1.0
   cmake/3.26.3-gcc-12.1.0			    libfabric/1.18.0-gcc-12.1.0        netlib-lapack/3.11.0-gcc-12.1.0				      pkgconf/1.9.5-gcc-12.1.0	       py-pyproject-hooks/1.0.0-gcc-12.1.0	 util-macros/1.19.3-gcc-12.1.0
   diffutils/3.9-gcc-12.1.0			    libffi/3.4.4-gcc-12.1.0	       netlib-scalapack/2.2.0-gcc-12.1.0-netlib-lapack-mpich	      pmix/4.2.3-gcc-12.1.0	       py-pyproject-metadata/0.7.1-gcc-12.1.0	 xz/5.4.1-gcc-12.1.0
   expat/2.5.0-gcc-12.1.0			    libiconv/1.17-gcc-12.1.0	       netlib-scalapack/2.2.0-gcc-12.1.0-netlib-lapack-openmpi	      py-beniget/0.4.1-gcc-12.1.0      py-pythran/0.12.0-gcc-12.1.0-openblas	 yaksa/0.2-gcc-12.1.0
   findutils/4.9.0-gcc-12.1.0			    libmd/1.0.4-gcc-12.1.0	       netlib-scalapack/2.2.0-gcc-12.1.0-openblas-mpich 	      py-build/0.10.0-gcc-12.1.0       py-scipy/1.10.1-gcc-12.1.0-openblas	 zlib/1.2.13-gcc-12.1.0
   gcc/12.1.0-gcc-11.3.0			    libpciaccess/0.17-gcc-12.1.0       netlib-scalapack/2.2.0-gcc-12.1.0-openblas-openmpi      (D)    py-cython/0.29.33-gcc-12.1.0     py-setuptools/63.4.3-gcc-12.1.0		 zstd/1.5.5-gcc-12.1.0
   gdbm/1.23-gcc-12.1.0 			    libsigsegv/2.14-gcc-12.1.0	       ninja/1.11.1-gcc-12.1.0					      py-flit-core/3.7.1-gcc-12.1.0    py-tomli/2.0.1-gcc-12.1.0
   gettext/0.21.1-gcc-12.1.0			    libtool/2.4.7-gcc-12.1.0	       numactl/2.0.14-gcc-12.1.0				      py-gast/0.5.3-gcc-12.1.0	       py-wheel/0.37.1-gcc-12.1.0

  Where:
   D:  Default Module

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

This layout is quite simple to deploy, but you can see from the above snippet that nothing prevents users from loading incompatible sets of modules:

$ module purge
$ module load netlib-lapack openblas
$ module list

Currently Loaded Modules:
  1) netlib-lapack/3.11.0-gcc-12.1.0   2) openblas/0.3.23-gcc-12.1.0

Even if conflicts directives are carefully placed in module files, they:

  • won’t enforce a consistent environment, but will just report an error
  • need constant updates, for instance as soon as a new compiler or MPI library is installed

Hierarchical module files try to overcome these shortcomings by showing at start-up only a restricted view of what is available on the system: more specifically only the software that has been installed with OS provided compilers. Among this software there will be other - usually more recent - compilers that, once loaded, will prepend new directories to MODULEPATH unlocking all the software that was compiled with them. This “unlocking” idea can then be extended arbitrarily to virtual dependencies, as we’ll see in the following section.

Core/Compiler/MPI

The most widely used hierarchy is the so called Core/Compiler/MPI where, on top of the compilers, different MPI libraries also unlock software linked to them. There are just a few steps needed to adapt the modules.yaml file we used previously:

  1. enable the lmod file generator
  2. change the tcl tag to lmod
  3. remove the tcl specific conflict directive
  4. declare which compilers are considered core_compilers
  5. remove the mpi related suffixes in projections (as they will be substituted by hierarchies)

After these modifications your configuration file should look like:

modules:
  default:
    enable::
      - lmod
    lmod:
      core_compilers:
      - 'gcc@11'
      hierarchy:
      - mpi
      hash_length: 0
      include:
      - gcc
      exclude:
      - '%gcc@11.3.0'
      all:
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"
        environment:
          set:
            '{name}_ROOT': '{prefix}'
      openmpi:
        environment:
          set:
            SLURM_MPI_TYPE: pmi2
            OMPI_MCA_btl_openib_warn_default_gid_prefix: '0'
      projections:
        all:          '{name}/{version}'
        ^lapack:      '{name}/{version}-{^lapack.name}'

Note

Double colon in configuration files
The double colon after enable is intentional and it serves the purpose of overriding the default list of enabled generators so that only lmod will be active (see Overriding entire sections for more details).

The directive core_compilers accepts a list of compilers. Everything built using these compilers will create a module in the Core part of the hierarchy, which is the entry point for hierarchical module files. It is common practice to put the OS provided compilers in the list and only build common utilities and other compilers with them.

If we now regenerate the module files:

$ spack module lmod refresh --delete-tree -y
==> Regenerating lmod module files

and update MODULEPATH to point to the Core:

$ module purge
$ module unuse $HOME/spack/share/spack/modules/linux-ubuntu18.04-x86_64
$ module use $HOME/spack/share/spack/lmod/linux-ubuntu18.04-x86_64/Core

asking for the available modules will return:

$ module avail

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/Core --------------------------------------------------------------------------------------------------------
   gcc/12.1.0

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

Unsurprisingly, the only visible module is gcc. Loading that we’ll unlock the Compiler part of the hierarchy:

$ module load gcc
$ module avail

---------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/gcc/12.1.0 -----------------------------------------------------------------------------------------------------
   autoconf/2.69			 diffutils/3.9	    krb5/1.20.1 	    libmd/1.0.4 	 meson/1.1.0		 openmpi/4.1.5	   py-beniget/0.4.1	       py-packaging/23.0	      py-scipy/1.10.1-openblas	  sqlite/3.40.1 	    zstd/1.5.5
   automake/1.16.5			 expat/2.5.0	    libbsd/0.11.7	    libpciaccess/0.17	 mpich/4.1.1		 openssh/9.3p1	   py-build/0.10.0	       py-pip/23.0		      py-setuptools/63.4.3	  tar/1.34
   berkeley-db/18.1.40			 findutils/4.9.0    libedit/3.1-20210216    libsigsegv/2.14	 ncurses/6.4		 openssl/1.1.1t    py-cython/0.29.33	       py-ply/3.11		      py-tomli/2.0.1		  util-linux-uuid/2.38.1
   bison/3.8.2				 gdbm/1.23	    libevent/2.1.12	    libtool/2.4.7	 netlib-lapack/3.11.0	 perl/5.36.0	   py-flit-core/3.7.1	       py-pybind11/2.10.1	      py-wheel/0.37.1		  util-macros/1.19.3
   bzip2/1.0.8				 gettext/0.21.1     libfabric/1.18.0	    libxcrypt/4.4.33	 ninja/1.11.1		 pigz/2.7	   py-gast/0.5.3	       py-pyproject-hooks/1.0.0       python/3.10.10		  xz/5.4.1
   ca-certificates-mozilla/2023-01-10	 gmake/4.4.1	    libffi/3.4.4	    libxml2/2.10.3	 numactl/2.0.14 	 pkgconf/1.9.5	   py-meson-python/0.12.0      py-pyproject-metadata/0.7.1    re2c/2.2			  yaksa/0.2
   cmake/3.26.3 			 hwloc/2.9.1	    libiconv/1.17	    m4/1.4.19		 openblas/0.3.23	 pmix/4.2.3	   py-numpy/1.24.3-openblas    py-pythran/0.12.0-openblas     readline/8.2		  zlib/1.2.13

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/Core --------------------------------------------------------------------------------------------------------
   gcc/12.1.0 (L)

  Where:
   L:  Module is loaded

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

The same holds true also for the MPI part, that you can enable by loading either mpich or openmpi. Let’s start by loading mpich:

$ module load mpich
$ module avail

------------------------------------------------------------------------------------------ /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/mpich/4.1.1-fb4tt65/gcc/12.1.0 -------------------------------------------------------------------------------------------
   netlib-scalapack/2.2.0-netlib-lapack    netlib-scalapack/2.2.0-openblas (D)

---------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/gcc/12.1.0 -----------------------------------------------------------------------------------------------------
   autoconf/2.69			 expat/2.5.0		libedit/3.1-20210216	    libtool/2.4.7		ninja/1.11.1	   pkgconf/1.9.5	     py-numpy/1.24.3-openblas	    py-scipy/1.10.1-openblas	tar/1.34
   automake/1.16.5			 findutils/4.9.0	libevent/2.1.12 	    libxcrypt/4.4.33		numactl/2.0.14	   pmix/4.2.3		     py-packaging/23.0		    py-setuptools/63.4.3	util-linux-uuid/2.38.1
   berkeley-db/18.1.40			 gdbm/1.23		libfabric/1.18.0     (L)    libxml2/2.10.3	 (L)	openblas/0.3.23    py-beniget/0.4.1	     py-pip/23.0		    py-tomli/2.0.1		util-macros/1.19.3
   bison/3.8.2				 gettext/0.21.1 	libffi/3.4.4		    m4/1.4.19			openmpi/4.1.5	   py-build/0.10.0	     py-ply/3.11		    py-wheel/0.37.1		xz/5.4.1	       (L)
   bzip2/1.0.8				 gmake/4.4.1		libiconv/1.17	     (L)    meson/1.1.0 		openssh/9.3p1	   py-cython/0.29.33	     py-pybind11/2.10.1 	    python/3.10.10		yaksa/0.2	       (L)
   ca-certificates-mozilla/2023-01-10	 hwloc/2.9.1	 (L)	libmd/1.0.4		    mpich/4.1.1 	 (L)	openssl/1.1.1t	   py-flit-core/3.7.1	     py-pyproject-hooks/1.0.0	    re2c/2.2			zlib/1.2.13	       (L)
   cmake/3.26.3 			 krb5/1.20.1		libpciaccess/0.17    (L)    ncurses/6.4 	 (L)	perl/5.36.0	   py-gast/0.5.3	     py-pyproject-metadata/0.7.1    readline/8.2		zstd/1.5.5
   diffutils/3.9			 libbsd/0.11.7		libsigsegv/2.14 	    netlib-lapack/3.11.0	pigz/2.7	   py-meson-python/0.12.0    py-pythran/0.12.0-openblas     sqlite/3.40.1

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/Core --------------------------------------------------------------------------------------------------------
   gcc/12.1.0 (L)

  Where:
   D:  Default Module
   L:  Module is loaded

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".
$ module load openblas netlib-scalapack/2.2.0-openblas
$ module list

Currently Loaded Modules:
  1) gcc/12.1.0   2) libpciaccess/0.17	 3) libiconv/1.17   4) xz/5.4.1   5) zlib/1.2.13   6) libxml2/2.10.3   7) ncurses/6.4	8) hwloc/2.9.1	 9) libfabric/1.18.0  10) yaksa/0.2  11) mpich/4.1.1  12) openblas/0.3.23  13) netlib-scalapack/2.2.0-openblas

At this point we can showcase the improved consistency that a hierarchical layout provides over a non-hierarchical one:

$ export LMOD_AUTO_SWAP=yes
$ module load openmpi

Lmod is automatically replacing "mpich/4.1.1" with "openmpi/4.1.5".


Due to MODULEPATH changes, the following have been reloaded:
  1) netlib-scalapack/2.2.0-openblas

Lmod took care of swapping the MPI provider for us, and it also substituted the netlib-scalapack module to conform to the change in the MPI. In this way we can’t accidentally pull-in two different MPI providers at the same time or load a module file for a package linked to openmpi when mpich is also loaded. Consistency for compilers and MPI is ensured by the tool.

Add LAPACK to the hierarchy

The hierarchy just shown is already a great improvement over non-hierarchical layouts, but it still has an asymmetry: LAPACK providers cover the same semantic role as MPI providers, but yet they are not part of the hierarchy.

To be more practical, this means that although we have gained an improved consistency in our environment when it comes to MPI, we still have the same problems as we had before for LAPACK implementations:

$ module list

Currently Loaded Modules:
  1) gcc/12.1.0        3) libpciaccess/0.17   5) xz/5.4.1      7) libxml2/2.10.3   9) hwloc/2.9.1     11) bzip2/1.0.8  13) zstd/1.5.5  15) gettext/0.21.1  17) krb5/1.20.1	     19) libxcrypt/4.4.33  21) libevent/2.1.12	23) openmpi/4.1.5
  2) openblas/0.3.23   4) libiconv/1.17       6) zlib/1.2.13   8) ncurses/6.4	  10) numactl/2.0.14  12) pigz/2.7     14) tar/1.34    16) openssl/1.1.1t  18) libedit/3.1-20210216  20) openssh/9.3p1	   22) pmix/4.2.3	24) netlib-scalapack/2.2.0-openblas



$ module avail

----------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/openmpi/4.1.5-ekmi64f/gcc/12.1.0 ------------------------------------------------------------------------------------------
   netlib-scalapack/2.2.0-netlib-lapack    netlib-scalapack/2.2.0-openblas (L,D)

---------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/gcc/12.1.0 -----------------------------------------------------------------------------------------------------
   autoconf/2.69			     expat/2.5.0	    libedit/3.1-20210216 (L)	libtool/2.4.7		    ninja/1.11.1	   pkgconf/1.9.5		 py-numpy/1.24.3-openblas	py-scipy/1.10.1-openblas    tar/1.34		   (L)
   automake/1.16.5			     findutils/4.9.0	    libevent/2.1.12	 (L)	libxcrypt/4.4.33     (L)    numactl/2.0.14  (L)    pmix/4.2.3		  (L)	 py-packaging/23.0		py-setuptools/63.4.3	    util-linux-uuid/2.38.1
   berkeley-db/18.1.40			     gdbm/1.23		    libfabric/1.18.0		libxml2/2.10.3	     (L)    openblas/0.3.23 (L)    py-beniget/0.4.1		 py-pip/23.0			py-tomli/2.0.1		    util-macros/1.19.3
   bison/3.8.2				     gettext/0.21.1  (L)    libffi/3.4.4		m4/1.4.19		    openmpi/4.1.5   (L)    py-build/0.10.0		 py-ply/3.11			py-wheel/0.37.1 	    xz/5.4.1		   (L)
   bzip2/1.0.8			      (L)    gmake/4.4.1	    libiconv/1.17	 (L)	meson/1.1.0		    openssh/9.3p1   (L)    py-cython/0.29.33		 py-pybind11/2.10.1		python/3.10.10		    yaksa/0.2
   ca-certificates-mozilla/2023-01-10	     hwloc/2.9.1     (L)    libmd/1.0.4 		mpich/4.1.1		    openssl/1.1.1t  (L)    py-flit-core/3.7.1		 py-pyproject-hooks/1.0.0	re2c/2.2		    zlib/1.2.13 	   (L)
   cmake/3.26.3 			     krb5/1.20.1     (L)    libpciaccess/0.17	 (L)	ncurses/6.4	     (L)    perl/5.36.0 	   py-gast/0.5.3		 py-pyproject-metadata/0.7.1	readline/8.2		    zstd/1.5.5		   (L)
   diffutils/3.9			     libbsd/0.11.7	    libsigsegv/2.14		netlib-lapack/3.11.0	    pigz/2.7	    (L)    py-meson-python/0.12.0	 py-pythran/0.12.0-openblas	sqlite/3.40.1

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/Core --------------------------------------------------------------------------------------------------------
   gcc/12.1.0 (L)

  Where:
   D:  Default Module
   L:  Module is loaded

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".


$ module load netlib-scalapack/2.2.0-netlib-lapack

The following have been reloaded with a version change:
  1) netlib-scalapack/2.2.0-openblas => netlib-scalapack/2.2.0-netlib-lapack

$ module list

Currently Loaded Modules:
  1) gcc/12.1.0 	 4) libiconv/1.17   7) libxml2/2.10.3  10) numactl/2.0.14  13) zstd/1.5.5      16) openssl/1.1.1t	 19) libxcrypt/4.4.33  22) pmix/4.2.3		 25) netlib-scalapack/2.2.0-netlib-lapack
  2) openblas/0.3.23	 5) xz/5.4.1	    8) ncurses/6.4     11) bzip2/1.0.8	   14) tar/1.34        17) krb5/1.20.1		 20) openssh/9.3p1     23) openmpi/4.1.5
  3) libpciaccess/0.17	 6) zlib/1.2.13     9) hwloc/2.9.1     12) pigz/2.7	   15) gettext/0.21.1  18) libedit/3.1-20210216  21) libevent/2.1.12   24) netlib-lapack/3.11.0

Hierarchies that are deeper than Core/Compiler/MPI are probably still considered “unusual” or “impractical” at many sites, mainly because module files are written manually and keeping track of the combinations among multiple providers quickly becomes quite involved.

For instance, having both MPI and LAPACK in the hierarchy means we must classify software into one of four categories:

  1. Software that doesn’t depend on MPI or LAPACK
  2. Software that depends only on MPI
  3. Software that depends only on LAPACK
  4. Software that depends on both

to decide when to show it to the user. The situation becomes more involved as the number of virtual dependencies in the hierarchy increases.

We can take advantage of the DAG that Spack maintains for the installed software and solve this combinatorial problem in a clean and automated way. In some sense Spack’s ability to manage this combinatorial complexity makes deeper hierarchies feasible.

Coming back to our example, let’s add lapack to the hierarchy and remove the remaining suffix projection for lapack:

modules:
  default:
    enable::
    - lmod
    lmod:
      core_compilers:
      - 'gcc@11'
      hierarchy:
      - mpi
      - lapack
      hash_length: 0
      include:
      - gcc
      exclude:
      - '%gcc@11.3.0'
      all:
        filter:
          exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"
        environment:
          set:
            '{name}_ROOT': '{prefix}'
      openmpi:
        environment:
          set:
            SLURM_MPI_TYPE: pmi2
            OMPI_MCA_btl_openib_warn_default_gid_prefix: '0'
      projections:
        all:          '{name}/{version}'

After module files have been regenerated as usual:

$ module purge
$ spack module lmod refresh --delete-tree -y
==> Regenerating lmod module files

we can see that now we have additional components in the hierarchy:

$ module load gcc

Lmod is automatically replacing "openblas/0.3.23" with "netlib-lapack/3.11.0".


Inactive Modules:
  1) netlib-scalapack/2.2.0-netlib-lapack     2) openblas

$ module load openblas

Lmod is automatically replacing "netlib-lapack/3.11.0" with "openblas/0.3.23".


Activating Modules:
  1) openblas/0.3.23

$ module avail

----------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/openmpi/4.1.5-ekmi64f/openblas/0.3.23-5hvwk3g/gcc/12.1.0 ------------------------------------------------------------------------------
   netlib-scalapack/2.2.0

---------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/openblas/0.3.23-5hvwk3g/gcc/12.1.0 -----------------------------------------------------------------------------------------
   py-numpy/1.24.3    py-pythran/0.12.0    py-scipy/1.10.1

---------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/gcc/12.1.0 -----------------------------------------------------------------------------------------------------
   autoconf/2.69			     expat/2.5.0	    libedit/3.1-20210216 (L)	libtool/2.4.7		    ninja/1.11.1	   pkgconf/1.9.5		 py-packaging/23.0		py-wheel/0.37.1 	      xz/5.4.1	  (L)
   automake/1.16.5			     findutils/4.9.0	    libevent/2.1.12	 (L)	libxcrypt/4.4.33     (L)    numactl/2.0.14  (L)    pmix/4.2.3		  (L)	 py-pip/23.0			python/3.10.10		      yaksa/0.2
   berkeley-db/18.1.40			     gdbm/1.23		    libfabric/1.18.0		libxml2/2.10.3	     (L)    openblas/0.3.23 (L)    py-beniget/0.4.1		 py-ply/3.11			re2c/2.2		      zlib/1.2.13 (L)
   bison/3.8.2				     gettext/0.21.1  (L)    libffi/3.4.4		m4/1.4.19		    openmpi/4.1.5   (L)    py-build/0.10.0		 py-pybind11/2.10.1		readline/8.2		      zstd/1.5.5  (L)
   bzip2/1.0.8			      (L)    gmake/4.4.1	    libiconv/1.17	 (L)	meson/1.1.0		    openssh/9.3p1   (L)    py-cython/0.29.33		 py-pyproject-hooks/1.0.0	sqlite/3.40.1
   ca-certificates-mozilla/2023-01-10	     hwloc/2.9.1     (L)    libmd/1.0.4 		mpich/4.1.1		    openssl/1.1.1t  (L)    py-flit-core/3.7.1		 py-pyproject-metadata/0.7.1	tar/1.34	       (L)
   cmake/3.26.3 			     krb5/1.20.1     (L)    libpciaccess/0.17	 (L)	ncurses/6.4	     (L)    perl/5.36.0 	   py-gast/0.5.3		 py-setuptools/63.4.3		util-linux-uuid/2.38.1
   diffutils/3.9			     libbsd/0.11.7	    libsigsegv/2.14		netlib-lapack/3.11.0	    pigz/2.7	    (L)    py-meson-python/0.12.0	 py-tomli/2.0.1 		util-macros/1.19.3

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/Core --------------------------------------------------------------------------------------------------------
   gcc/12.1.0 (L)

  Where:
   L:  Module is loaded

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".


$ module load openmpi
$ module avail

----------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/openmpi/4.1.5-ekmi64f/openblas/0.3.23-5hvwk3g/gcc/12.1.0 ------------------------------------------------------------------------------
   netlib-scalapack/2.2.0

---------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/openblas/0.3.23-5hvwk3g/gcc/12.1.0 -----------------------------------------------------------------------------------------
   py-numpy/1.24.3    py-pythran/0.12.0    py-scipy/1.10.1

---------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/gcc/12.1.0 -----------------------------------------------------------------------------------------------------
   autoconf/2.69			     expat/2.5.0	    libedit/3.1-20210216 (L)	libtool/2.4.7		    ninja/1.11.1	   pkgconf/1.9.5		 py-packaging/23.0		py-wheel/0.37.1 	      xz/5.4.1	  (L)
   automake/1.16.5			     findutils/4.9.0	    libevent/2.1.12	 (L)	libxcrypt/4.4.33     (L)    numactl/2.0.14  (L)    pmix/4.2.3		  (L)	 py-pip/23.0			python/3.10.10		      yaksa/0.2
   berkeley-db/18.1.40			     gdbm/1.23		    libfabric/1.18.0		libxml2/2.10.3	     (L)    openblas/0.3.23 (L)    py-beniget/0.4.1		 py-ply/3.11			re2c/2.2		      zlib/1.2.13 (L)
   bison/3.8.2				     gettext/0.21.1  (L)    libffi/3.4.4		m4/1.4.19		    openmpi/4.1.5   (L)    py-build/0.10.0		 py-pybind11/2.10.1		readline/8.2		      zstd/1.5.5  (L)
   bzip2/1.0.8			      (L)    gmake/4.4.1	    libiconv/1.17	 (L)	meson/1.1.0		    openssh/9.3p1   (L)    py-cython/0.29.33		 py-pyproject-hooks/1.0.0	sqlite/3.40.1
   ca-certificates-mozilla/2023-01-10	     hwloc/2.9.1     (L)    libmd/1.0.4 		mpich/4.1.1		    openssl/1.1.1t  (L)    py-flit-core/3.7.1		 py-pyproject-metadata/0.7.1	tar/1.34	       (L)
   cmake/3.26.3 			     krb5/1.20.1     (L)    libpciaccess/0.17	 (L)	ncurses/6.4	     (L)    perl/5.36.0 	   py-gast/0.5.3		 py-setuptools/63.4.3		util-linux-uuid/2.38.1
   diffutils/3.9			     libbsd/0.11.7	    libsigsegv/2.14		netlib-lapack/3.11.0	    pigz/2.7	    (L)    py-meson-python/0.12.0	 py-tomli/2.0.1 		util-macros/1.19.3

------------------------------------------------------------------------------------------------------- /home/spack/spack/share/spack/lmod/linux-ubuntu22.04-x86_64/Core --------------------------------------------------------------------------------------------------------
   gcc/12.1.0 (L)

  Where:
   L:  Module is loaded

If the avail list is too long consider trying:

"module --default avail" or "ml -d av" to just list the default modules.
"module overview" or "ml ov" to display the number of modules for each name.

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching any of the "keys".

Both MPI and LAPACK providers will now benefit from the same safety features:

$ module load py-numpy netlib-scalapack

Activating Modules:
  1) netlib-scalapack/2.2.0

$ module load mpich

Lmod is automatically replacing "openmpi/4.1.5" with "mpich/4.1.1".


Due to MODULEPATH changes, the following have been reloaded:
  1) netlib-scalapack/2.2.0

$ module load netlib-lapack

Lmod is automatically replacing "openblas/0.3.23" with "netlib-lapack/3.11.0".


Inactive Modules:
  1) bzip2/1.0.8     3) gdbm/1.23	   5) libbsd/0.11.7	7) libmd/1.0.4		9) openssl/1.1.1t    11) py-numpy		 13) python/3.10.10    15) sqlite/3.40.1    17) util-linux-uuid/2.38.1
  2) expat/2.5.0     4) gettext/0.21.1	   6) libffi/3.4.4	8) libxcrypt/4.4.33    10) pigz/2.7	     12) py-setuptools/63.4.3	 14) readline/8.2      16) tar/1.34	    18) zstd/1.5.5

Due to MODULEPATH changes, the following have been reloaded:
  1) netlib-scalapack/2.2.0

Because we only compiled py-numpy with openblas the module is made inactive when we switch the LAPACK provider. The user environment is now consistent by design!

Working with Templates

As briefly mentioned in the introduction, Spack uses Jinja2 to generate each individual module file. This means that you have all of its flexibility and power when it comes to customizing what gets generated!

Module file templates

The templates that Spack uses to generate module files are stored in the share/spack/templates/module directory within the Spack prefix, and they all share the same common structure. Usually, they start with a header that identifies the type of module being generated. In the case of hierarchical module files it’s:

-- -*- lua -*-
-- Module file created by spack (https://github.com/spack/spack) on {{ timestamp }}
--
-- {{ spec.short_spec }}
--

The statements within double curly brackets {{ ... }} denote expressions that will be evaluated and substituted at module generation time. The rest of the file is then divided into blocks that can be overridden or extended by users, if need be. Control structures , delimited by {% ... %}, are also permitted in the template language:

{% elif command_name == 'AppendPath' %}
append_path("{{ cmd.name }}", "{{ cmd.value }}", "{{ cmd.separator }}")
{% elif command_name == 'RemovePath' %}
remove_path("{{ cmd.name }}", "{{ cmd.value }}", "{{ cmd.separator }}")
{% elif command_name == 'SetEnv' %}
setenv("{{ cmd.name }}", "{{ cmd.value }}")
{% elif command_name == 'UnsetEnv' %}
unsetenv("{{ cmd.name }}")
{% endif %}
{% endfor %}
{% endblock %}

{% block footer %}
{# In case the module needs to be extended with custom LUA code #}
{% endblock %}

The locations where Spack looks for templates are specified in config.yaml:

  # Locations where templates should be found
  template_dirs:
    - $spack/share/spack/templates

and can be extended by users to employ custom templates, as we’ll see next.

Extend the default templates

Let’s assume one of our software is protected by group membership: allowed users belong to the same linux group, and access is granted at group level. Wouldn’t it be nice if people that are not yet entitled to use it could receive a helpful message at module load time that tells them who to contact in your organization to be inserted in the group?

To automate the generation of module files with such site-specific behavior we’ll start by extending the list of locations where Spack looks for module files. Let’s create the file ${SPACK_ROOT}/etc/spack/config.yaml with the content:

config:
  template_dirs:
    - $HOME/.spack/templates

This tells Spack to also search another location when looking for template files. Next, we need to create our custom template extension in the folder listed above:

{% extends "modules/modulefile.lua" %}
{% block footer %}
-- Access is granted only to specific groups
if not isDir("{{ spec.prefix }}") then
    LmodError (
        "You don't have the necessary rights to run \"{{ spec.name }}\".\n\n",
        "\tPlease write an e-mail to 1234@foo.com if you need further information on how to get access to it.\n"
    )
end
{% endblock %}

Let’s name this file group-restricted.lua. The line:

{% extends "modules/modulefile.lua" %}

tells Jinja2 that we are reusing the standard template for hierarchical module files. The section:

{% block footer %}
-- Access is granted only to specific groups
if not isDir("{{ spec.prefix }}") then
    LmodError (
        "You don't have the necessary rights to run \"{{ spec.name }}\".\n\n",
        "\tPlease write an e-mail to 1234@foo.com if you need further information on how to get access to it.\n"
    )
end
{% endblock %}

overrides the footer block. Finally, we need to add a couple of lines in modules.yaml to tell Spack which specs need to use the new custom template. For the sake of illustration let’s assume it’s netlib-scalapack:

modules:
  enable::
    - lmod
  lmod:
    core_compilers:
      - 'gcc@11'
    hierarchy:
      - mpi
      - lapack
    hash_length: 0
    include:
      - gcc
    exclude:
      - '%gcc@11.3.0'
      - readline
    all:
      filter:
        exclude_env_vars:
          - "C_INCLUDE_PATH"
          - "CPLUS_INCLUDE_PATH"
          - "LIBRARY_PATH"
      environment:
        set:
          '{name}_ROOT': '{prefix}'
    openmpi:
      environment:
        set:
          SLURM_MPI_TYPE: pmi2
          OMPI_MCA_btl_openib_warn_default_gid_prefix: '0'
    netlib-scalapack:
      template: 'group-restricted.lua'

If we regenerate the module files one last time:

$ spack module lmod refresh -y netlib-scalapack
==> Regenerating lmod module files

we’ll find the following at the end of each netlib-scalapack module file:

-- Access is granted only to specific groups
if not isDir("/home/spack/spack/opt/spack/linux-ubuntu18.04-x86_64/gcc-12.1.0/netlib-scalapack-2.0.2-2p75lzqjbsnev7d2j2osgpkz7ib33oca") then
    LmodError (
        "You don't have the necessary rights to run \"netlib-scalapack\".\n\n",
        "\tPlease write an e-mail to 1234@foo.com if you need further information on how to get access to it.\n"
    )
end

and every user that doesn’t have access to the software will now be redirected to the right e-mail address where to ask for it!

Restore settings for future sections

For future sections of the tutorial, we will not use the gcc@12.1.0 compiler. Since it is currently the default compiler (our current default is the most recent version of gcc available), we will remove it now.

$ spack compiler rm gcc@12.1.0

This will ensure the rest of the tutorial goes smoothly for you.