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:
4.7.0 https://download.osgeo.org/libtiff/tiff-4.7.0.tar.gz
Safe versions:
4.7.0 https://download.osgeo.org/libtiff/tiff-4.7.0.tar.gz
Deprecated versions:
4.6.0 https://download.osgeo.org/libtiff/tiff-4.6.0.tar.gz
4.5.1 https://download.osgeo.org/libtiff/tiff-4.5.1.tar.gz
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
Variants:
build_system [cmake] autotools, cmake
Build systems supported by the package
ccitt [true] false, true
support for CCITT Group 3 & 4 algorithms
jbig [false] false, true
use ISO JBIG compression
jpeg [true] false, true
use libjpeg
logluv [true] false, true
support for LogLuv high dynamic range algorithm
lzw [true] false, true
support for LZW algorithm
next [true] false, true
support for NeXT 2-bit RLE algorithm
old-jpeg [false] false, true
support for Old JPEG compression
packbits [true] false, true
support for Macintosh PackBits algorithm
pic [false] false, true
Enable position-independent code (PIC)
pixarlog [false] false, true
support for Pixar log-format algorithm
shared [true] false, true
Build shared
thunder [true] false, true
support for ThunderScan 4-bit RLE algorithm
zlib [true] false, true
use zlib
when build_system=cmake
build_type [Release] Debug, MinSizeRel, RelWithDebInfo, Release
CMake build type
generator [make] none
the build system generator to use
when build_system=cmake ^cmake@3.9:
ipo [false] false, true
CMake interprocedural optimization
when @4.5,4.7:
opengl [false] false, true
use OpenGL (required for tiffgt viewer)
when @4.2:
libdeflate [false] false, true
use libdeflate
when @4:
jpeg12 [false] false, true
enable libjpeg 8/12-bit dual mode
lzma [false] false, true
use liblzma
when @4.3:
lerc [false] false, true
use libLerc
when @4.0.10:
webp [false] false, true
use libwebp
zstd [false] false, true
use libzstd
Build Dependencies:
cmake gmake gnuconfig jbigkit jpeg lerc libwebp ninja xz zlib-api zstd
Link Dependencies:
jbigkit jpeg lerc libwebp xz zlib-api zstd
Run Dependencies:
None
Licenses:
libtiff
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 Debug. Basically, be as awkward as possible and change everything:
spack install --deprecated libtiff@4.4.0 +webp -jpeg build_type=Debug
There we’re just turned on a feature (webp), turned off a feature (jpeg), and told it we want the Debug build type. Have a look through the references to get further information, but this is actually the basics of choosing variants of packages.
Even worse here, we’re choosing to install a version that Spack really
recommends against. Deprecated software potentially has been marked as such
because of security issues, so you likely want to avoid these, but if you know
best --deprecated allows you to install them anyway. I’ll revert to a more
sensible recommended version in the later examples!
Compilers#
You may want to build a package with a different compiler, that you already have configured.
spack install libtiff@4.7.0 +webp -jpeg %gcc@11.4.1
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@4.7.0 +webp -jpeg build_type=Release ^perl@5.36.0 %gcc@11.4.1
This would build using Perl 5.36.0, without JPEG support, and with WebP support, using the GCC 11.4.1 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
- atop@2.5.0%gcc@14.2.0 build_system=generic arch=linux-rocky9-zen4
[+] ^gcc-runtime@14.2.0%gcc@14.2.0 build_system=generic arch=linux-rocky9-zen4
[e] ^glibc@2.34%gcc@14.2.0 build_system=autotools arch=linux-rocky9-zen4
[+] ^ncurses@6.5%gcc@14.2.0~symlinks+termlib abi=none build_system=autotools patches=7a351bc arch=linux-rocky9-zen4
[+] ^gmake@4.4.1%gcc@11.4.1~guile build_system=generic arch=linux-rocky9-zen4
[+] ^pkgconf@2.2.0%gcc@14.2.0 build_system=autotools arch=linux-rocky9-zen4
[+] ^zlib-ng@2.2.1%gcc@11.4.1+compat+new_strategies+opt+pic+shared build_system=autotools arch=linux-rocky9-zen4
[+] ^gcc-runtime@11.4.1%gcc@11.4.1 build_system=generic arch=linux-rocky9-zen4
[e] ^glibc@2.34%gcc@11.4.1 build_system=autotools arch=linux-rocky9-zen4
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:
3.4 https://github.com/tmux/tmux/releases/download/3.4/tmux-3.4.tar.gz
Safe versions:
master [git] https://github.com/tmux/tmux.git on branch master
3.4 https://github.com/tmux/tmux/releases/download/3.4/tmux-3.4.tar.gz
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:
build_system [autotools] autotools
Build systems supported by the package
static [false] false, true
Create a static build
utf8proc [false] false, true
Build with UTF-8 support from utf8proc library
Build Dependencies:
autoconf automake gmake gnuconfig libevent ncurses pkgconfig utf8proc yacc
Link Dependencies:
autoconf automake libevent ncurses utf8proc
Run Dependencies:
None
Licenses:
ISC
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-rocky9-zen4 / gcc@14.2.0 -------------------------------
tmux@3.2a~static+utf8proc build_system=autotools patches=c1b61a1
==> 1 installed package
You can see from this that we’re using the shiny new 3.2a version, and can confirm that it was built with UTF-8 support included.