Developer Workflows Tutorial¶
This tutorial will guide you through the process of using the spack dev-build command to manage dependencies while developing software. This will allow you to install a package from local source, develop that source code, and iterate on the different phases of your build system as necessary.
Prepare for the tutorial¶
If you have already done the :ref:_basics-tutorial you have probably already set up Spack to run in the tutorial image. If not, you will want to run the following commands:
$ git clone https://github.com/spack/spack $ cd spack $ git checkout releases/v0.13 $ . share/spack/setup-env.sh $ spack mirror add tutorial /mirror $ spack gpg trust /mirror/public.key
These commands install Spack into your home directory, add Spack to your path, and configure Spack to make use of the binary packages published for this tutorial.
Installing from local source¶
The spack install command, as you know, fetches source code from a mirror or the internet before building and installing your package. As developers, we want to build from local source, which we will constantly change, build, and test.
Let’s imagine for a second we’re HDF5 developers.
$ cd ~ $ git clone https://bitbucket.hdfgroup.org/scm/hdffv/hdf5.git $ cd hdf5
Here we have the local HDF5 source that we’ve been working on. If we
want to build and install it, we can do so using the
dev-build command. Note that we need to provide a version in the
spec we pass to
spack dev-build. By default, the
dev-build command will print verbose output from the build system to
$ spack dev-build hdf5@develop ~mpi ... ==> Installing hdf5 ==> Searching for binary cache of hdf5 ==> Finding buildcaches in /Users/becker33/mirror/build_cache ==> No binary for hdf5 found: installing from source ==> No need to fetch for DIY. ==> No checksum needed for DIY. ==> Sources for DIY stages are not cached ==> Using source directory: /Users/becker33/hdf5 ==> No patches needed for hdf5 ==> Building hdf5 [AutotoolsPackage] ==> Executing phase: 'autoreconf' ==> [2019-10-28-15:08:15.788680] './autogen.sh' ************************** * HDF5 autogen.sh script * ************************** Running trace script: ... ==> Successfully installed hdf5 Fetch: 0.00s. Build: 2m 33.28s. Total: 2m 33.28s. [+] /Users/becker33/spack/opt/spack/darwin-mojave-x86_64/clang-9.0.0-apple/hdf5-develop-ncccarpcwda4zgirtricb7psqikcbrc4
Done! HDF5 is installed.
So what’s going on here? When we use the spack dev-build command,
Spack still manages the package’s dependencies as it would for the
spack install command. The dependencies for HDF5 are all
installed, either from binary or source, if they were not
already. Instead of downloading the source code for HDF5, Spack
constructed a stage in the current directory to use the local
source. Spack then constructed the build environment and arguments for
the HDF5 build system as it would for the
command. The resulting installation is added to Spack’s database as
usual, and post-install hooks including modulefile generation are ran
Development iteration cycles¶
Generally, as developers, we only want to configure our package once,
and then we want to iterate developing and building our code, before
installing it once if at all. We can do this in Spack using the
-u/--until option with the
spack dev-build command. To do this
we need to know the phases of the build that Spack will
use. Fortunately, as experienced HDF5 developers we all happen to know
that those phases are
install. If we don’t remember the phases, we could find out using
spack info command.
$ spack info hdf5 AutotoolsPackage: hdf5 Description: HDF5 is a data model, library, and file format for storing and managing data. It supports an unlimited variety of datatypes, and is designed for flexible and efficient I/O and for high volume and complex data. Homepage: https://support.hdfgroup.org/HDF5/ Tags: None Preferred version: 1.10.5 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.5/src/hdf5-1.10.5.tar.gz Safe versions: develop [git] https://bitbucket.hdfgroup.org/scm/hdffv/hdf5.git on branch develop 1.10.5 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.5/src/hdf5-1.10.5.tar.gz 1.10.4 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.4/src/hdf5-1.10.4.tar.gz 1.10.3 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.3/src/hdf5-1.10.3.tar.gz 1.10.2 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.2/src/hdf5-1.10.2.tar.gz 1.10.1 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.1/src/hdf5-1.10.1.tar.gz 1.10.0-patch1 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.0-patch1/src/hdf5-1.10.0-patch1.tar.gz 1.10.0 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.10/hdf5-1.10.0/src/hdf5-1.10.0.tar.gz 1.8.21 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.21/src/hdf5-1.8.21.tar.gz 1.8.19 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.19/src/hdf5-1.8.19.tar.gz 1.8.18 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.18/src/hdf5-1.8.18.tar.gz 1.8.17 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.17/src/hdf5-1.8.17.tar.gz 1.8.16 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.16/src/hdf5-1.8.16.tar.gz 1.8.15 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.15/src/hdf5-1.8.15.tar.gz 1.8.14 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.14/src/hdf5-1.8.14.tar.gz 1.8.13 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.13/src/hdf5-1.8.13.tar.gz 1.8.12 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.12/src/hdf5-1.8.12.tar.gz 1.8.10 https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.10/src/hdf5-1.8.10.tar.gz Variants: Name [Default] Allowed values Description cxx [off] True, False Enable C++ support debug [off] True, False Builds a debug version of the library fortran [off] True, False Enable Fortran support hl [off] True, False Enable the high-level library mpi [on] True, False Enable MPI support pic [on] True, False Produce position-independent code (for shared libs) shared [on] True, False Builds a shared version of the library szip [off] True, False Enable szip support threadsafe [off] True, False Enable thread-safe capabilities Installation Phases: autoreconf configure build install Build Dependencies: autoconf automake libtool m4 mpi szip zlib Link Dependencies: mpi szip zlib Run Dependencies: None Virtual Packages: None
We will tell Spack to stop installing HDF5 after the
stage. This will execute exactly the same as before, except it will
stop the installation after the listed, in our case
$ spack dev-build --until configure hdf5@develop +hl ~mpi
Now, we can develop our code. For the sake of this demo, we’re just going to intentionally introduce an error. Let’s edit a file and remove the first semi-colon we find.
$ $EDITOR src/H5D.c
To build our code, we have a couple options. We could use spack dev-build and the -u option to configure and build our code, but we’ve already configured our code, and the changes we made don’t affect the build system. Instead, let’s run our build system directly – we are developers of this code now, after all. The first thing we need to do is activate Spack’s build environment for our code:
$ spack build-env hdf5@develop +hl ~mpi -- bash $ make Making all in src ... H5D.c:55:32: error: expected ';' after top level declarator hbool_t H5_PKG_INIT_VAR = FALSE ^ ; 1 error generated. make: *** [H5D.lo] Error 1 make: *** [all] Error 2 make: *** [all-recursive] Error 1
This is exactly what we’d expect, since we broke the code on purpose. Now let’s fix it and rebuild directly.
$ $EDITOR src/H5D.c $ make Making all in src ... make: Nothing to be done for `all-am'. make: Nothing to be done for `all-am'.
We’ve now used Spack to install all of our dependencies and configure our code, but we can have a faster development cycle using our build system directly.
spack dev-build command with the
-u/--until option and
spack build-env command to setup all your dependencies with
Spack and iterate using your native build system as Spack would use it.