Advanced software install#
Spack takes a number of decisions itself about how to build software, and what dependencies to use. You’re able to adjust some of this via variants within an individual package, but also you can tweak the dependency decisions, to use different packages if you know better than the defaults.
Variants#
Variants are where the package has options how to build it. Let’s pick on
libtiff as a nice example. You can get information on a package in Spack,
which will tell you about how it can be built:
$ spack info libtiff
CMakePackage: libtiff
Description:
LibTIFF - Tag Image File Format (TIFF) Library and Utilities.
Homepage: http://www.simplesystems.org/libtiff/
Preferred version:
4.5.0 https://download.osgeo.org/libtiff/tiff-4.5.0.tar.gz
Safe versions:
4.5.0 https://download.osgeo.org/libtiff/tiff-4.5.0.tar.gz
4.4.0 https://download.osgeo.org/libtiff/tiff-4.4.0.tar.gz
4.3.0 https://download.osgeo.org/libtiff/tiff-4.3.0.tar.gz
4.2.0 https://download.osgeo.org/libtiff/tiff-4.2.0.tar.gz
4.1.0 https://download.osgeo.org/libtiff/tiff-4.1.0.tar.gz
4.0.10 https://download.osgeo.org/libtiff/tiff-4.0.10.tar.gz
4.0.9 https://download.osgeo.org/libtiff/tiff-4.0.9.tar.gz
4.0.8 https://download.osgeo.org/libtiff/tiff-4.0.8.tar.gz
4.0.7 https://download.osgeo.org/libtiff/tiff-4.0.7.tar.gz
4.0.6 https://download.osgeo.org/libtiff/tiff-4.0.6.tar.gz
4.0.5 https://download.osgeo.org/libtiff/tiff-4.0.5.tar.gz
4.0.4 https://download.osgeo.org/libtiff/tiff-4.0.4.tar.gz
3.9.7 https://download.osgeo.org/libtiff/tiff-3.9.7.tar.gz
Deprecated versions:
None
Variants:
Name [Default] When Allowed values Description
==================== ============================== ==================== ===============================================
build_system [cmake] -- cmake, autotools Build systems supported by the package
build_type [Release] [build_system=cmake] Debug, Release, CMake build type
RelWithDebInfo,
MinSizeRel
ccitt [on] -- on, off support for CCITT Group 3 & 4 algorithms
generator [make] [build_system=cmake] ninja,make the build system generator to use
ipo [off] [build_system=cmake on, off CMake interprocedural optimization
^cmake@3.9:]
jbig [off] -- on, off use ISO JBIG compression
jpeg [on] -- on, off use libjpeg
jpeg12 [off] [@4:] on, off enable libjpeg 8/12-bit dual mode
lerc [off] [@4.3:] on, off use libLerc
libdeflate [off] [@4.2:] on, off use libdeflate
logluv [on] -- on, off support for LogLuv high dynamic range algorithm
lzma [off] [@4:] on, off use liblzma
lzw [on] -- on, off support for LZW algorithm
next [on] -- on, off support for NeXT 2-bit RLE algorithm
old-jpeg [off] -- on, off support for Old JPEG compression
packbits [on] -- on, off support for Macintosh PackBits algorithm
pixarlog [off] -- on, off support for Pixar log-format algorithm
thunder [on] -- on, off support for ThunderScan 4-bit RLE algorithm
webp [off] [@4.0.10:] on, off use libwebp
zlib [on] -- on, off use zlib
zstd [off] [@4.0.10:] on, off use libzstd
Build Dependencies:
cmake gmake gnuconfig jbigkit jpeg lerc libwebp ninja xz zlib zstd
Link Dependencies:
jbigkit jpeg lerc libwebp xz zlib zstd
Run Dependencies:
None
From this you can see that there’s lots of versions available, and there’s a number of variants listed, along with dependencies. Let’s say I wanted to build version 4.4.0, and we want webp support to be on, jpeg support to be off, and a build_type of Release. Basically, be as awkward as possible and change everything:
spack install libtiff @4.4.0 +webp -jpeg build_type=Release
There we’re just turned on a feature (webp), turned off a feature (jpeg), and told it we want the Release build type. Have a look through the references to get further information, but this is actually the basics of choosing variants of packages.
Compilers#
You may want to build a package with a different compiler, that you already have configured.
spack install libtiff @4.4.0 +webp -jpeg build_type=Release %gcc@4.8.5
Now Spack will happily rebuild that specific variant you’ve asked for, with the compiler you’ve asked for.
Dependencies#
You can also specify particular versions and variants of dependencies. We can take our previous build even further:
spack install libtiff @4.4.0 +webp -jpeg build_type=Release ^perl@5.30.0 %gcc@4.8.5
This would build using Perl 5.30.0, without JPEG support, and with WebP support, using the GNU 4.8.5 compiler. Note that we have used a ^ to say which version of perl we want to use because it’s a package that we depend on, whereas we have to use % to say which compiler to use.
Previewing a software install#
Before installing a piece of software, you can review what Spack is planning on doing, and which dependencies it’s going to rely on.
$ spack spec atop
Input spec
--------------------------------
atop
Concretized
--------------------------------
atop@2.5.0%gcc@12.3.0 build_system=generic arch=linux-centos7-skylake_avx512
^ncurses@6.4%gcc@12.3.0~symlinks+termlib abi=none build_system=autotools arch=linux-centos7-skylake_avx512
^pkgconf@1.9.5%gcc@12.3.0 build_system=autotools arch=linux-centos7-skylake_avx512
^zlib@1.2.13%gcc@12.3.0+optimize+pic+shared build_system=makefile arch=linux-centos7-skylake_avx512
This way you can verify which versions it’s expecting to use, and can adjust your installation parameters if anything needs changing.
Notes#
In some instances you may find that Spack’s desire to reuse existing modules
doesn’t fit with what you want, and you want it to rebuild exactly as you’ve
asked. In that instance, you can simply add the argument --fresh which tells
Spack to work out dependencies ignoring what’s already been built, and select
what it thinks is optimal.
You’ll note in our section on simplifying the modules system, we simplified it to the point that the naming scheme used was name/version. This loses all details about variants, making it impossible to distinguish between variants. If you only ever build one particular instance of a module, this isn’t a problem, but if you’re wanting to switch between multiple variants, or with different compilers, you’ll either want to stick with the original scheme, or look at alternative naming schemes that can capture the necessary detail.
Exercise#
Install tmux version 3.2a with UTF-8 support.
Click here to reveal solution
Solution#
First you need to look at the info for tmux, to find out what variants are available. Some of the output below has been truncated for brevity:
$ spack info tmux
AutotoolsPackage: tmux
Description:
Tmux is a terminal multiplexer. What is a terminal multiplexer? It lets
you switch easily between several programs in one terminal, detach them
(they keep running in the background) and reattach them to a different
terminal. And do a lot more.
Homepage: https://tmux.github.io
Preferred version:
3.3a https://github.com/tmux/tmux/releases/download/3.3a/tmux-3.3a.tar.gz
Safe versions:
master [git] https://github.com/tmux/tmux.git on branch master
3.3a https://github.com/tmux/tmux/releases/download/3.3a/tmux-3.3a.tar.gz
3.2a https://github.com/tmux/tmux/releases/download/3.2a/tmux-3.2a.tar.gz
3.2 https://github.com/tmux/tmux/releases/download/3.2/tmux-3.2.tar.gz
3.1c https://github.com/tmux/tmux/releases/download/3.1c/tmux-3.1c.tar.gz
3.1b https://github.com/tmux/tmux/releases/download/3.1b/tmux-3.1b.tar.gz
3.1a https://github.com/tmux/tmux/releases/download/3.1a/tmux-3.1a.tar.gz
3.1 https://github.com/tmux/tmux/releases/download/3.1/tmux-3.1.tar.gz
3.0a https://github.com/tmux/tmux/releases/download/3.0a/tmux-3.0a.tar.gz
3.0 https://github.com/tmux/tmux/releases/download/3.0/tmux-3.0.tar.gz
2.9a https://github.com/tmux/tmux/releases/download/2.9a/tmux-2.9a.tar.gz
2.9 https://github.com/tmux/tmux/releases/download/2.9/tmux-2.9.tar.gz
2.8 https://github.com/tmux/tmux/releases/download/2.8/tmux-2.8.tar.gz
2.7 https://github.com/tmux/tmux/releases/download/2.7/tmux-2.7.tar.gz
2.6 https://github.com/tmux/tmux/releases/download/2.6/tmux-2.6.tar.gz
2.5 https://github.com/tmux/tmux/releases/download/2.5/tmux-2.5.tar.gz
2.4 https://github.com/tmux/tmux/releases/download/2.4/tmux-2.4.tar.gz
2.3 https://github.com/tmux/tmux/releases/download/2.3/tmux-2.3.tar.gz
2.2 https://github.com/tmux/tmux/releases/download/2.2/tmux-2.2.tar.gz
2.1 https://github.com/tmux/tmux/releases/download/2.1/tmux-2.1.tar.gz
1.9a https://github.com/tmux/tmux/releases/download/1.9a/tmux-1.9a.tar.gz
Deprecated versions:
None
Variants:
Name [Default] When Allowed values Description
======================== ==== ============== ==============================================
build_system [autotools] -- autotools Build systems supported by the package
static [off] -- on, off Create a static build
utf8proc [off] -- on, off Build with UTF-8 support from utf8proc library
Build Dependencies:
autoconf automake gnuconfig libevent ncurses pkgconfig utf8proc
Link Dependencies:
autoconf automake libevent ncurses utf8proc
Run Dependencies:
None
You can see from this that there is indeed a version 3.2a available, and to add UTF-8 support, you need to enable the utf8proc feature. That then gives an install command of:
spack install tmux@3.2a+utf8proc
If you’ve installed this and want to verify it’s worked:
$ spack load tmux
$ tmux -V
tmux 3.2a
$ spack find -v tmux
-- linux-centos7-skylake_avx512 / gcc@12.3.0 --------------------
tmux@3.2a~static+utf8proc build_system=autotools
==> 1 installed package
You can see from this that we’re using the shiny new 3.2 version, and can confirm that it was built with UTF-8 support included.