Basic Installation Tutorial

This tutorial will guide you through the process of installing software using Spack. We will first cover the spack install command, focusing on the power of the spec syntax and the flexibility it gives to users. We will also cover the spack find command for viewing installed packages and the spack uninstall command. Finally, we will touch on how Spack manages compilers, especially as it relates to using Spack-built compilers within Spack. We will include full output from all of the commands demonstrated, although we will frequently call attention to only small portions of that output (or merely to the fact that it succeeded). The provided output is all from a cluster running Red Hat Enterprise Linux.

Installing Spack

Spack works out of the box. Simply clone spack and get going.

$ git clone https://github.com/LLNL/spack.git
Initialized empty Git repository in ~/spack/.git/
remote: Counting objects: 47125, done.
remote: Compressing objects: 100% (68/68), done.
remote: Total 47125 (delta 16), reused 2 (delta 2), pack-reused 47047
Receiving objects: 100% (47125/47125), 12.02 MiB | 2.11 MiB/s, done.
Resolving deltas: 100% (23044/23044), done.
$ cd spack

Then add Spack to your path.

$ export PATH=~/spack/bin:$PATH

You’re good to go!

What is in Spack?

The spack list command shows available packages.

$ spack list
==> 1016 packages.
abinit                           hwloc                  piranha              r-rjava
ack                              hydra                  pixman               r-rjson
activeharmony                    hypre                  pkg-config           r-rjsonio
...

The spack list command can also take a query string. Spack automatically adds wildcards to both ends of the string. For example, we can view all available python packages.

$ spack list py
==> 129 packages.
py-3to2            py-epydoc          py-nestle         py-pycparser         py-six
py-alabaster       py-flake8          py-netcdf         py-pydatalog         py-sncosmo
py-argcomplete     py-funcsigs        py-networkx       py-pyelftools        py-snowballstemmer
...

Installing Packages

Installing a package with Spack is very simple. To install a piece of software, simply type spack install <package_name>

$ spack install libelf
==> Installing libelf
==> Trying to fetch from ~/spack/var/spack/cache/libelf/libelf-0.8.13.tar.gz
curl: (37) Couldn't open file ~/spack/var/spack/cache/libelf/libelf-0.8.13.tar.gz
==> Fetching from ~/spack/var/spack/cache/libelf/libelf-0.8.13.tar.gz failed.
==> Trying to fetch from http://www.mr511.de/software/libelf-0.8.13.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libelf-0.8.13-csrt4qxfkhjgn5xg3zjpkir7xdnszl2a/libelf-0.8.13.tar.gz
==> Created stage in ~/spack/var/spack/stage/libelf-0.8.13-csrt4qxfkhjgn5xg3zjpkir7xdnszl2a
==> No patches needed for libelf
==> Building libelf [Package]
==> Executing phase : 'install'
==> Successfully installed libelf
  Fetch: 1.21s.  Build: 8.42s.  Total: 9.62s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.13-csrt4qxfkhjgn5xg3zjpkir7xdnszl2a

Spack’s spec syntax is the interface by which we can request specific configurations of the package. The % sigil is used to specify compilers.

$ spack install libelf %intel
==> Installing libelf
==> Trying to fetch from ~/spack/var/spack/cache/libelf/libelf-0.8.13.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libelf-0.8.13-7wgp32xksatkvw2tbssmehw2t5tnxndj/libelf-0.8.13.tar.gz
==> Created stage in ~/spack/var/spack/stage/libelf-0.8.13-7wgp32xksatkvw2tbssmehw2t5tnxndj
==> No patches needed for libelf
==> Building libelf [Package]
==> Executing phase : 'install'
==> Successfully installed libelf
  Fetch: 0.09s.  Build: 50.64s.  Total: 50.72s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/intel-16.0.3/libelf-0.8.13-7wgp32xksatkvw2tbssmehw2t5tnxndj

Note that this installation is located separately from the previous one. We will discuss this in more detail later, but this is part of what allows Spack to support arbitrarily versioned software.

You can check for particular versions before requesting them. We will use the spack versions command to see the available versions, and then install a different version of libelf.

$ spack versions libelf
==> Safe versions (already checksummed):
  0.8.13
  0.8.12
==> Remote versions (not yet checksummed):
  0.8.11
  0.8.10
  0.8.9
  0.8.8
  0.8.7
  0.8.6
  0.8.5
  0.8.4
  0.8.3
  0.8.2
  0.8.0
  0.7.0
  0.6.4
  0.5.2

The @ sigil is used to specify versions, both of packages and of compilers.

$ spack install libelf @0.8.12
==> Installing libelf
==> Trying to fetch from ~/spack/var/spack/cache/libelf/libelf-0.8.12.tar.gz
curl: (37) Couldn't open file ~/spack/var/spack/cache/libelf/libelf-0.8.12.tar.gz
==> Fetching from ~/spack/var/spack/cache/libelf/libelf-0.8.12.tar.gz failed.
==> Trying to fetch from http://www.mr511.de/software/libelf-0.8.12.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libelf-0.8.12-ipggckv6i7h44iryzfa4dwdela32a7fy/libelf-0.8.12.tar.gz
==> Created stage in ~/spack/var/spack/stage/libelf-0.8.12-ipggckv6i7h44iryzfa4dwdela32a7fy
==> No patches needed for libelf
==> Building libelf [Package]
==> Executing phase : 'install'
==> Successfully installed libelf
  Fetch: 1.12s.  Build: 7.88s.  Total: 9.00s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.12-ipggckv6i7h44iryzfa4dwdela32a7fy



$ spack install libelf %intel@15.0.4
==> Installing libelf
==> Trying to fetch from ~/spack/var/spack/cache/libelf/libelf-0.8.13.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libelf-0.8.13-w33hrejdyqu2j2gggdswitls2zv6kdsi/libelf-0.8.13.tar.gz
==> Created stage in ~/spack/var/spack/stage/libelf-0.8.13-w33hrejdyqu2j2gggdswitls2zv6kdsi
==> No patches needed for libelf
==> Building libelf [Package]
==> Executing phase : 'install'
==> Successfully installed libelf
  Fetch: 0.09s.  Build: 55.51s.  Total: 55.60s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/intel-15.0.4/libelf-0.8.13-w33hrejdyqu2j2gggdswitls2zv6kdsi

The spec syntax also includes compiler flags. Spack accepts cppflags, cflags, cxxflags, fflags, ldflags, and ldlibs parameters. The values of these fields must be quoted on the command line if they include spaces. These values are injected into the compile line automatically by the Spack compiler wrappers.

$ spack install libelf @0.8.12 cppflags="-O3"
==> Installing libelf
==> Trying to fetch from ~/spack/var/spack/cache/libelf/libelf-0.8.12.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libelf-0.8.12-vrv2ttbd34xlfoxy4jwt6qsjrcbalmmw/libelf-0.8.12.tar.gz
==> Created stage in ~/spack/var/spack/stage/libelf-0.8.12-vrv2ttbd34xlfoxy4jwt6qsjrcbalmmw
==> No patches needed for libelf
==> Building libelf [Package]
==> Executing phase : 'install'
==> Successfully installed libelf
  Fetch: 0.04s.  Build: 7.95s.  Total: 7.99s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.12-vrv2ttbd34xlfoxy4jwt6qsjrcbalmmw

The spack find command is used to query installed packages. Note that some packages appear identical with the default output. The -l flag shows the hash of each package, and the -f flag shows any non-empty compiler flags of those packages.

$ spack find
==> 5 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
libelf@0.8.12
libelf@0.8.12
libelf@0.8.13

-- linux-redhat6-x86_64 / intel@15.0.4 --------------------------
libelf@0.8.13

-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
libelf@0.8.13



$ spack find -lf
==> 5 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
ipggckv libelf@0.8.12%gcc

vrv2ttb libelf@0.8.12%gcc cppflags="-O3"

csrt4qx libelf@0.8.13%gcc


-- linux-redhat6-x86_64 / intel@15.0.4 --------------------------
w33hrej libelf@0.8.13%intel


-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
7wgp32x libelf@0.8.13%intel

Spack generates a hash for each spec. This hash is a function of the full provenance of the package, so any change to the spec affects the hash. Spack uses this value to compare specs and to generate unique installation directories for every combinatorial version. As we move into more complicated packages with software dependencies, we can see that Spack reuses existing packages to satisfy a dependency only when the existing package’s hash matches the desired spec.

$ spack install libdwarf
==> Installing libdwarf
==> libelf is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.13-csrt4qxfkhjgn5xg3zjpkir7xdnszl2a
==> Can not find version 20160507 in url_list
==> Trying to fetch from ~/spack/var/spack/cache/libdwarf/libdwarf-20160507.tar.gz
curl: (37) Couldn't open file ~/spack/var/spack/cache/libdwarf/libdwarf-20160507.tar.gz
==> Fetching from ~/spack/var/spack/cache/libdwarf/libdwarf-20160507.tar.gz failed.
==> Trying to fetch from http://www.prevanders.net/libdwarf-20160507.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libdwarf-20160507-yfx6p3g3rkmqvcqbmtb34o6pln7pqvcz/libdwarf-20160507.tar.gz
==> Created stage in ~/spack/var/spack/stage/libdwarf-20160507-yfx6p3g3rkmqvcqbmtb34o6pln7pqvcz
==> No patches needed for libdwarf
==> Building libdwarf [Package]
==> Executing phase : 'install'
==> Successfully installed libdwarf
  Fetch: 1.56s.  Build: 33.59s.  Total: 35.15s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libdwarf-20160507-yfx6p3g3rkmqvcqbmtb34o6pln7pqvcz

Dependencies can be explicitly requested using the ^ sigil. Note that the spec syntax is recursive. Anything we could specify about the top-level package, we can also specify about a dependency using ^.

$ spack install libdwarf ^libelf @0.8.12 %intel
==> Installing libdwarf
==> Installing libelf
==> Trying to fetch from ~/spack/var/spack/cache/libelf/libelf-0.8.12.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libelf-0.8.12-4blbe3qxqct3ymrfoxxnxysmybvbxay7/libelf-0.8.12.tar.gz
==> Created stage in ~/spack/var/spack/stage/libelf-0.8.12-4blbe3qxqct3ymrfoxxnxysmybvbxay7
==> No patches needed for libelf
==> Building libelf [Package]
==> Executing phase : 'install'
==> Successfully installed libelf
  Fetch: 0.04s.  Build: 52.16s.  Total: 52.19s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/intel-16.0.3/libelf-0.8.12-4blbe3qxqct3ymrfoxxnxysmybvbxay7
==> Can not find version 20160507 in url_list
==> Trying to fetch from ~/spack/var/spack/cache/libdwarf/libdwarf-20160507.tar.gz
################################################################################################################################################################################# 100.0%
==> Staging archive: ~/spack/var/spack/stage/libdwarf-20160507-csruprgucaujkfkrcywhwou7nbeis5fo/libdwarf-20160507.tar.gz
==> Created stage in ~/spack/var/spack/stage/libdwarf-20160507-csruprgucaujkfkrcywhwou7nbeis5fo
==> No patches needed for libdwarf
==> Building libdwarf [Package]
==> Executing phase : 'install'
==> Successfully installed libdwarf
  Fetch: 0.40s.  Build: 2m 17.29s.  Total: 2m 17.69s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/intel-16.0.3/libdwarf-20160507-csruprgucaujkfkrcywhwou7nbeis5fo

Packages can also be referred to from the command line by their package hash. Using the spack find -lf command earlier we saw that the hash of our optimized installation of libelf (cppflags="-O3") began with vrv2ttb. We can now explicitly build with that package without typing the entire spec, by using the / sigil to refer to it by hash. As with other tools like git, you do not need to specify an entire hash on the command line. You can specify just enough digits to identify a hash uniquely. If a hash prefix is ambiguous (i.e., two or more installed packages share the prefix) then spack will report an error.

$ spack install libdwarf ^/vrv2ttb
==> Installing libdwarf
==> libelf is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.12-vrv2ttbd34xlfoxy4jwt6qsjrcbalmmw
==> Can not find version 20160507 in url_list
==> Trying to fetch from ~/spack/var/spack/cache/libdwarf/libdwarf-20160507.tar.gz
#################################################################################################################################################################################################################################################### 100.0%
==> Staging archive: ~/spack/var/spack/stage/libdwarf-20160507-dtg3tgnp7htccoly26gduqlrgvnwcp5t/libdwarf-20160507.tar.gz
==> Created stage in ~/spack/var/spack/stage/libdwarf-20160507-dtg3tgnp7htccoly26gduqlrgvnwcp5t
==> No patches needed for libdwarf
==> Building libdwarf [Package]
==> Executing phase : 'install'
==> Successfully installed libdwarf
  Fetch: 0.96s.  Build: 24.03s.  Total: 24.99s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libdwarf-20160507-dtg3tgnp7htccoly26gduqlrgvnwcp5t

The spack find command can also take a -d flag, which can show dependency information. Note that each package has a top-level entry, even if it also appears as a dependency.

$ spack find -ldf
==> 9 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
dtg3tgn    libdwarf@20160507%gcc
vrv2ttb        ^libelf@0.8.12%gcc cppflags="-O3"

yfx6p3g    libdwarf@20160507%gcc
csrt4qx        ^libelf@0.8.13%gcc

ipggckv    libelf@0.8.12%gcc

vrv2ttb    libelf@0.8.12%gcc cppflags="-O3"

csrt4qx    libelf@0.8.13%gcc


-- linux-redhat6-x86_64 / intel@15.0.4 --------------------------
w33hrej    libelf@0.8.13%intel


-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
csruprg    libdwarf@20160507%intel
4blbe3q        ^libelf@0.8.12%intel

4blbe3q    libelf@0.8.12%intel

7wgp32x    libelf@0.8.13%intel

As we get to more complex packages, full installs will take too long to build in the time allotted for this tutorial. Our collaborators at CERN have been working on binary caching for Spack, which would allow for very fast installs of previously built packages. We are still working out the security ramifications of the feature, but it is coming soon.

For now, we will switch to doing “fake” installs. When supplied with the --fake flag (primarily used for debugging), Spack computes build metadata the same way it normally would, but it does not download the source or run the install script for a pacakge. We can use this to quickly demonstrate some of the more advanced Spack features in our limited tutorial time.

HDF5 is an example of a more complicated package, with an MPI dependency. If we install it “out of the box,” it will build with openmpi.

$ spack install --fake hdf5
==> Installing hdf5
==> Installing zlib
==> Building zlib [Package]
==> Successfully installed zlib
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Installing openmpi
==> Installing hwloc
==> Installing libpciaccess
==> Installing util-macros
==> Building util-macros [Package]
==> Successfully installed util-macros
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/util-macros-1.19.0-pc6zhs4cnkmg2cv4et4fizsp6scuvacg
==> Installing libtool
==> Installing m4
==> Installing libsigsegv
==> Building libsigsegv [Package]
==> Successfully installed libsigsegv
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libsigsegv-2.10-q4cok3yber7lhf3jswg6mysg7oi53unh
==> Building m4 [Package]
==> Successfully installed m4
  Fetch: .  Build: 0.23s.  Total: 0.23s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> Building libtool [Package]
==> Successfully installed libtool
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libtool-2.4.6-rdx5nkfjwlvcanz5il3ys2pe34j4vxx5
==> Installing pkg-config
==> Building pkg-config [Package]
==> Successfully installed pkg-config
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/pkg-config-0.29.1-wpjnlzahdw6ahkrgmqyeugkj2zhv4tui
==> Building libpciaccess [Package]
==> Successfully installed libpciaccess
  Fetch: .  Build: 0.10s.  Total: 0.10s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libpciaccess-0.13.4-m2f6fpm22rpprq2ihkmfx6llf363264m
==> Building hwloc [Package]
==> Successfully installed hwloc
  Fetch: .  Build: 0.23s.  Total: 0.23s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hwloc-1.11.4-xpb6hbl2hsze25cgdgfnoppn6rchhzaz
==> Building openmpi [Package]
==> Successfully installed openmpi
  Fetch: .  Build: 0.35s.  Total: 0.35s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openmpi-2.0.1-j4cgoq4furxvr73pq72r2qgywgksw3qn
==> Building hdf5 [AutotoolsPackage]
==> Successfully installed hdf5
  Fetch: .  Build: 0.61s.  Total: 0.61s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-ezvtnox35albuaxqryuondweyjgeo6es

Spack packages can also have variants. Boolean variants can be specified using the + and ~ or - sigils. There are two sigils for False to avoid conflicts with shell parsing in different situations. Variants (boolean or otherwise) can also be specified using the same syntax as compiler flags. Here we can install HDF5 without MPI support.

$ spack install --fake hdf5~mpi
==> Installing hdf5
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Building hdf5 [AutotoolsPackage]
==> Successfully installed hdf5
  Fetch: .  Build: 0.22s.  Total: 0.22s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-twppaioxqn6lti4grgopnmhwcq3h2rpw

We might also want to install HDF5 with a different MPI implementation. While MPI is not a package itself, packages can depend on abstract interfaces like MPI. Spack handles these through “virtual dependencies.” A package, such as HDF5, can depend on the MPI interface. Other packages (openmpi, mpich, mvapich, etc.) provide the MPI interface. Any of these providers can be requested for an MPI dependency. For example, we can build HDF5 with MPI support provided by mpich by specifying a dependency on mpich. Spack also supports versioning of virtual dependencies. A package can depend on the MPI interface at version 3, and provider packages specify what version of the interface they provide. The partial spec ^mpi@3 can be safisfied by any of several providers.

$ spack install --fake hdf5+mpi ^mpich
==> Installing hdf5
==> mpich is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpich-3.2-5jlp2ndnsb67txggraglu47vjmayx5za
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Building hdf5 [AutotoolsPackage]
==> Successfully installed hdf5
  Fetch: .  Build: 0.38s.  Total: 0.38s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-j36yfw25i6gdd3q4vwlupgkpwic4ua6m

We’ll do a quick check in on what we have installed so far.

$ spack find -ldf
==> 22 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
twppaio    hdf5@1.10.0-patch1%gcc
ayc4jq7        ^zlib@1.2.8%gcc

j36yfw2    hdf5@1.10.0-patch1%gcc
5jlp2nd        ^mpich@3.2%gcc
ayc4jq7        ^zlib@1.2.8%gcc

ezvtnox    hdf5@1.10.0-patch1%gcc
j4cgoq4        ^openmpi@2.0.1%gcc
xpb6hbl            ^hwloc@1.11.4%gcc
m2f6fpm                ^libpciaccess@0.13.4%gcc
ayc4jq7        ^zlib@1.2.8%gcc

xpb6hbl    hwloc@1.11.4%gcc
m2f6fpm        ^libpciaccess@0.13.4%gcc

dtg3tgn    libdwarf@20160507%gcc
vrv2ttb        ^libelf@0.8.12%gcc cppflags="-O3"

yfx6p3g    libdwarf@20160507%gcc
csrt4qx        ^libelf@0.8.13%gcc

ipggckv    libelf@0.8.12%gcc

vrv2ttb    libelf@0.8.12%gcc cppflags="-O3"

csrt4qx    libelf@0.8.13%gcc

m2f6fpm    libpciaccess@0.13.4%gcc

q4cok3y    libsigsegv@2.10%gcc

rdx5nkf    libtool@2.4.6%gcc

qijdzvh    m4@1.4.17%gcc
q4cok3y        ^libsigsegv@2.10%gcc

5jlp2nd    mpich@3.2%gcc

j4cgoq4    openmpi@2.0.1%gcc
xpb6hbl        ^hwloc@1.11.4%gcc
m2f6fpm            ^libpciaccess@0.13.4%gcc

wpjnlza    pkg-config@0.29.1%gcc

pc6zhs4    util-macros@1.19.0%gcc

ayc4jq7    zlib@1.2.8%gcc


-- linux-redhat6-x86_64 / intel@15.0.4 --------------------------
w33hrej    libelf@0.8.13%intel


-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
csruprg    libdwarf@20160507%intel
4blbe3q        ^libelf@0.8.12%intel

4blbe3q    libelf@0.8.12%intel

7wgp32x    libelf@0.8.13%intel

Spack models the dependencies of packages as a directed acyclic graph (DAG). The spack find -d command shows the tree representation of that graph. We can also use the spack graph command to view the entire DAG as a graph.

$ spack graph hdf5+mpi ^mpich
o  hdf5
|\
o |  zlib
 /
o  mpich

You may also have noticed that there are some packages shown in the spack find -d output that we didn’t install explicitly. These are dependencies that were installed implicitly. A few packages installed implicitly are not shown as dependencies in the spack find -d output. These are build dependencies. For example, libpciaccess is a dependency of openmpi and requires m4 to build. Spack will build m4` as part of the installation of openmpi, but it does not become a part of the DAG because it is not linked in at run time. Spack handles build dependencies differently because of their different (less strict) consistency requirements. It is entirely possible to have two packages using different versions of a dependency to build, which obviously cannot be done with linked dependencies.

HDF5 is more complicated than our basic example of libelf and libdwarf, but it’s still within the realm of software that an experienced HPC user could reasonably expect to install given a bit of time. Now let’s look at a more complicated package.

$ spack install --fake trilinos
==> Installing trilinos
==> Installing superlu-dist
==> openmpi is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openmpi-2.0.1-j4cgoq4furxvr73pq72r2qgywgksw3qn
==> Installing parmetis
==> openmpi is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openmpi-2.0.1-j4cgoq4furxvr73pq72r2qgywgksw3qn
==> Installing cmake
==> Installing bzip2
==> Building bzip2 [Package]
==> Successfully installed bzip2
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/bzip2-1.0.6-gll2xsahysy7ji5gkmfxwkofdt3mwjhs
==> expat is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/expat-2.2.0-mg5kwd3kluxdgorj32vzbp7aksg3vqej
==> Installing ncurses
==> Building ncurses [Package]
==> Successfully installed ncurses
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/ncurses-6.0-fttg4astvrtq2buey4wq66tnyu7bgj2c
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Installing openssl
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Building openssl [Package]
==> Successfully installed openssl
  Fetch: .  Build: 0.23s.  Total: 0.23s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openssl-1.0.2j-kt5xyk2dkho6tzadnqlbnbujmljprylg
==> Installing libarchive
==> Installing lzma
==> Building lzma [Package]
==> Successfully installed lzma
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/lzma-4.32.7-hah2cdo3zbulz6yg5do6dvnfn6en5v5c
==> Installing nettle
==> m4 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> Installing gmp
==> m4 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> Building gmp [AutotoolsPackage]
==> Successfully installed gmp
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gmp-6.1.1-uwn4gfdtq3sywy5uf4f7znrh66oybikf
==> Building nettle [Package]
==> Successfully installed nettle
  Fetch: .  Build: 0.18s.  Total: 0.18s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/nettle-3.2-w4ieitifcmrldo4ra7as63apagzf56ja
==> bzip2 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/bzip2-1.0.6-gll2xsahysy7ji5gkmfxwkofdt3mwjhs
==> expat is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/expat-2.2.0-mg5kwd3kluxdgorj32vzbp7aksg3vqej
==> Installing libxml2
==> Installing xz
==> Building xz [Package]
==> Successfully installed xz
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/xz-5.2.2-bxh6cpyqqozazm5okvjqk23sww3gccnf
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Building libxml2 [Package]
==> Successfully installed libxml2
  Fetch: .  Build: 0.35s.  Total: 0.35s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libxml2-2.9.4-un323rppyu5qipkegyf7flmymvtmunrx
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Installing lz4
==> Building lz4 [Package]
==> Successfully installed lz4
  Fetch: .  Build: 0.12s.  Total: 0.12s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/lz4-131-ivy2fcaw7ywujx74weebdi5bsm7q4vkc
==> openssl is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openssl-1.0.2j-kt5xyk2dkho6tzadnqlbnbujmljprylg
==> xz is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/xz-5.2.2-bxh6cpyqqozazm5okvjqk23sww3gccnf
==> Installing lzo
==> Building lzo [AutotoolsPackage]
==> Successfully installed lzo
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/lzo-2.09-dlgnm74ozo6baactkft5oah2jre2ri2i
==> Building libarchive [Package]
==> Successfully installed libarchive
  Fetch: .  Build: 1.35s.  Total: 1.35s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libarchive-3.2.1-biq3kebw7vel7njusill7vv7mjldkqjv
==> xz is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/xz-5.2.2-bxh6cpyqqozazm5okvjqk23sww3gccnf
==> Installing curl
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> openssl is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openssl-1.0.2j-kt5xyk2dkho6tzadnqlbnbujmljprylg
==> Building curl [Package]
==> Successfully installed curl
  Fetch: .  Build: 0.36s.  Total: 0.36s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/curl-7.50.3-oze4gqutj4x2isbkcn5ob2bhhxbskod4
==> Building cmake [Package]
==> Successfully installed cmake
  Fetch: .  Build: 1.64s.  Total: 1.64s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> Installing metis
==> cmake is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> Building metis [Package]
==> Successfully installed metis
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/metis-5.1.0-ithifyl4xvqbn76js23wsb4tjnztrbdv
==> Building parmetis [Package]
==> Successfully installed parmetis
  Fetch: .  Build: 0.62s.  Total: 0.62s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/parmetis-4.0.3-rtg6hml5t6acdcnxomn3l5zfiful4d2t
==> Installing openblas
==> Building openblas [Package]
==> Successfully installed openblas
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> metis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/metis-5.1.0-ithifyl4xvqbn76js23wsb4tjnztrbdv
==> Building superlu-dist [Package]
==> Successfully installed superlu-dist
  Fetch: .  Build: 0.85s.  Total: 0.85s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/superlu-dist-5.1.1-25r6jlvkpjnkiuwt2rtbzhk3l3htuxs7
==> cmake is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> Installing glm
==> cmake is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> Building glm [Package]
==> Successfully installed glm
  Fetch: .  Build: 0.12s.  Total: 0.12s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/glm-0.9.7.1-7a6oho4aerz7vftxd5ur7lywscht2iry
==> Installing hypre
==> openmpi is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openmpi-2.0.1-j4cgoq4furxvr73pq72r2qgywgksw3qn
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> Building hypre [Package]
==> Successfully installed hypre
  Fetch: .  Build: 0.61s.  Total: 0.61s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hypre-2.11.1-lf7hcejiiww5peesh57quda72z67veit
==> metis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/metis-5.1.0-ithifyl4xvqbn76js23wsb4tjnztrbdv
==> Installing netlib-scalapack
==> openmpi is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openmpi-2.0.1-j4cgoq4furxvr73pq72r2qgywgksw3qn
==> cmake is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> Building netlib-scalapack [Package]
==> Successfully installed netlib-scalapack
  Fetch: .  Build: 0.61s.  Total: 0.61s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/netlib-scalapack-2.0.2-dvcanz2qq4dfcexznbhbmzbxfj43uz4q
==> Installing suite-sparse
==> Installing tbb
==> Building tbb [Package]
==> Successfully installed tbb
  Fetch: .  Build: 0.12s.  Total: 0.12s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/tbb-4.4.4-zawzkkhrmdonbjpj3a5bb6gkgnqlrjeu
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> metis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/metis-5.1.0-ithifyl4xvqbn76js23wsb4tjnztrbdv
==> Building suite-sparse [Package]
==> Successfully installed suite-sparse
  Fetch: .  Build: 0.49s.  Total: 0.49s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/suite-sparse-4.5.3-lvur6hriy2j7xfjwh5punp3exwpynzm6
==> openmpi is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openmpi-2.0.1-j4cgoq4furxvr73pq72r2qgywgksw3qn
==> Installing netcdf
==> m4 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> curl is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/curl-7.50.3-oze4gqutj4x2isbkcn5ob2bhhxbskod4
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> hdf5 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-ezvtnox35albuaxqryuondweyjgeo6es
==> Building netcdf [Package]
==> Successfully installed netcdf
  Fetch: .  Build: 0.90s.  Total: 0.90s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/netcdf-4.4.1-tcl4zbrmdfrit2cqlaxig6xieu5h552j
==> Installing mumps
==> netlib-scalapack is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/netlib-scalapack-2.0.2-dvcanz2qq4dfcexznbhbmzbxfj43uz4q
==> openmpi is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openmpi-2.0.1-j4cgoq4furxvr73pq72r2qgywgksw3qn
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> Building mumps [Package]
==> Successfully installed mumps
  Fetch: .  Build: 0.74s.  Total: 0.74s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mumps-5.0.2-kr5r4nnx5tfcacxnk3ii5dsxbe6pu5fy
==> Installing matio
==> Building matio [Package]
==> Successfully installed matio
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/matio-1.5.2-4zrozucookychlvc4q53omp2zyfk2bed
==> Installing boost
==> bzip2 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/bzip2-1.0.6-gll2xsahysy7ji5gkmfxwkofdt3mwjhs
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> Building boost [Package]
==> Successfully installed boost
  Fetch: .  Build: 0.35s.  Total: 0.35s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/boost-1.62.0-je7eqvzt74kezwhh55y5lwt5dy6pnali
==> parmetis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/parmetis-4.0.3-rtg6hml5t6acdcnxomn3l5zfiful4d2t
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> hdf5 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-ezvtnox35albuaxqryuondweyjgeo6es
==> Building trilinos [Package]
==> Successfully installed trilinos
  Fetch: .  Build: 2.63s.  Total: 2.63s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/trilinos-12.8.1-uvd6dfd7x4uyvck4awo3r3frudihn4ar

Now we’re starting to see the power of Spack. Trilinos has 11 top level dependecies, many of which have dependencies of their own. Installing more complex packages can take days or weeks even for an experienced user. Although we’ve done a fake installation for the tutorial, a real installation of trilinos using Spack takes about 3 hours (depending on the system), but only 20 seconds of programmer time.

Spack manages constistency of the entire DAG. Every MPI dependency will be satisfied by the same configuration of MPI, etc. If we install trilinos again specifying a dependency on our previous HDF5 built with mpich:

$ spack install --fake trilinos ^hdf5+mpi ^mpich
==> Installing trilinos
==> Installing superlu-dist
==> mpich is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpich-3.2-5jlp2ndnsb67txggraglu47vjmayx5za
==> metis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/metis-5.1.0-ithifyl4xvqbn76js23wsb4tjnztrbdv
==> Installing parmetis
==> mpich is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpich-3.2-5jlp2ndnsb67txggraglu47vjmayx5za
==> metis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/metis-5.1.0-ithifyl4xvqbn76js23wsb4tjnztrbdv
==> cmake is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> Building parmetis [Package]
==> Successfully installed parmetis
  Fetch: .  Build: 0.38s.  Total: 0.38s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/parmetis-4.0.3-43kbtni6p5y446c6qdkybq4htj7ot4zn
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> Building superlu-dist [Package]
==> Successfully installed superlu-dist
  Fetch: .  Build: 0.61s.  Total: 0.61s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/superlu-dist-5.1.1-46uuupehmonx5jicc6xnegnud2n5jqyl
==> cmake is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> glm is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/glm-0.9.7.1-7a6oho4aerz7vftxd5ur7lywscht2iry
==> Installing hypre
==> mpich is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpich-3.2-5jlp2ndnsb67txggraglu47vjmayx5za
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> Building hypre [Package]
==> Successfully installed hypre
  Fetch: .  Build: 0.37s.  Total: 0.37s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hypre-2.11.1-6ajnyymoivs5apajd7thjisae36jv4lz
==> metis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/metis-5.1.0-ithifyl4xvqbn76js23wsb4tjnztrbdv
==> Installing netlib-scalapack
==> mpich is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpich-3.2-5jlp2ndnsb67txggraglu47vjmayx5za
==> cmake is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/cmake-3.6.1-n2nkknrku6dvuneo3rjumim7axt7n36e
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> Building netlib-scalapack [Package]
==> Successfully installed netlib-scalapack
  Fetch: .  Build: 0.37s.  Total: 0.37s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/netlib-scalapack-2.0.2-dayeep27omm26wksd3iqvbu3gezc2eoh
==> suite-sparse is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/suite-sparse-4.5.3-lvur6hriy2j7xfjwh5punp3exwpynzm6
==> Installing netcdf
==> m4 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> curl is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/curl-7.50.3-oze4gqutj4x2isbkcn5ob2bhhxbskod4
==> zlib is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/zlib-1.2.8-ayc4jq7vxuzge5n444gutvskeytfdruh
==> hdf5 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-j36yfw25i6gdd3q4vwlupgkpwic4ua6m
==> Building netcdf [Package]
==> Successfully installed netcdf
  Fetch: .  Build: 0.67s.  Total: 0.67s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/netcdf-4.4.1-gfemi4jk4qltvp33xhtpkam7dozbqvhq
==> Installing mumps
==> mpich is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpich-3.2-5jlp2ndnsb67txggraglu47vjmayx5za
==> netlib-scalapack is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/netlib-scalapack-2.0.2-dayeep27omm26wksd3iqvbu3gezc2eoh
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> Building mumps [Package]
==> Successfully installed mumps
  Fetch: .  Build: 0.49s.  Total: 0.49s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mumps-5.0.2-w7t5pl3jhhwitfiyer63zj6zv7idkt3m
==> mpich is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpich-3.2-5jlp2ndnsb67txggraglu47vjmayx5za
==> matio is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/matio-1.5.2-4zrozucookychlvc4q53omp2zyfk2bed
==> boost is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/boost-1.62.0-je7eqvzt74kezwhh55y5lwt5dy6pnali
==> parmetis is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/parmetis-4.0.3-43kbtni6p5y446c6qdkybq4htj7ot4zn
==> openblas is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/openblas-0.2.19-bwofa7fhff6od5zn56vy3j4eeyupsqgt
==> hdf5 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-j36yfw25i6gdd3q4vwlupgkpwic4ua6m
==> Building trilinos [Package]
==> Successfully installed trilinos
  Fetch: .  Build: 2.42s.  Total: 2.42s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/trilinos-12.8.1-ffwrpxnq7lhiw2abxn2u7ffr4jjsdwep

We see that every package in the trilinos DAG that depends on MPI now uses mpich.

$ spack find -d trilinos
==> 2 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
    trilinos@12.8.1
        ^boost@1.62.0
            ^bzip2@1.0.6
            ^zlib@1.2.8
        ^glm@0.9.7.1
        ^hdf5@1.10.0-patch1
            ^mpich@3.2
        ^hypre@2.11.1
            ^openblas@0.2.19
        ^matio@1.5.2
        ^metis@5.1.0
        ^mumps@5.0.2
            ^netlib-scalapack@2.0.2
        ^netcdf@4.4.1
            ^curl@7.50.3
                ^openssl@1.0.2j
        ^parmetis@4.0.3
        ^suite-sparse@4.5.3
            ^tbb@4.4.4
        ^superlu-dist@5.1.1

    trilinos@12.8.1
        ^boost@1.62.0
            ^bzip2@1.0.6
            ^zlib@1.2.8
        ^glm@0.9.7.1
        ^hdf5@1.10.0-patch1
            ^openmpi@2.0.1
                ^hwloc@1.11.4
                    ^libpciaccess@0.13.4
        ^hypre@2.11.1
            ^openblas@0.2.19
        ^matio@1.5.2
        ^metis@5.1.0
        ^mumps@5.0.2
            ^netlib-scalapack@2.0.2
        ^netcdf@4.4.1
            ^curl@7.50.3
                ^openssl@1.0.2j
        ^parmetis@4.0.3
        ^suite-sparse@4.5.3
            ^tbb@4.4.4
        ^superlu-dist@5.1.1

As we discussed before, the spack find -d command shows the dependency information as a tree. While that is often sufficient, many complicated packages, including trilinos, have dependencies that cannot be fully represented as a tree. Again, the spack graph command shows the full DAG of the dependency information.

$ spack graph trilinos
o  trilinos
|\
| |\
| | |\
| | | |\
| | | | |\
| | | | | |\
| | | | | | |\
| o | | | | | |  netcdf
| |\ \ \ \ \ \ \
| | |\ \ \ \ \ \ \
| | | o | | | | | |  curl
| | |/| | | | | | |
| |/| | | | | | | |
| | | o | | | | | |  openssl
| | |/ / / / / / /
| |/| | | | | | |
| | o | | | | | |  hdf5
| |/| | | | | | |
| | |/ / / / / /
| o | | | | | |  zlib
|  / / / / / /
o | | | | | |  swig
o | | | | | |  pcre
 / / / / / /
o | | | | |  mpi
 / / / / /
o | | | |  matio
 / / / /
o | | |  lapack
 / / /
o | |  glm
 / /
o |  boost
 /
o  blas

You can control how the output is displayed with a number of options.

The ASCII output from spack graph can be difficult to parse for complicated packages. The output can be changed to the graphviz .dot format using the –dot flag.

$ spack graph --dot trilinos | dot -Tpdf trilinos_graph.pdf

Uninstalling Packages

Earlier we installed many configurations each of libelf and libdwarf. Now we will go through and uninstall some of those packages that we didn’t really need.

$ spack find -d libdwarf
==> 3 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
    libdwarf@20160507
        ^libelf@0.8.12

    libdwarf@20160507
        ^libelf@0.8.13


-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
    libdwarf@20160507
        ^libelf@0.8.12

$ spack find libelf
==> 6 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
libelf@0.8.12  libelf@0.8.12  libelf@0.8.13

-- linux-redhat6-x86_64 / intel@15.0.4 --------------------------
libelf@0.8.13

-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
libelf@0.8.12  libelf@0.8.13

We can uninstall packages by spec using the same syntax as install.

$ spack uninstall libelf%intel@15.0.4
==> The following packages will be uninstalled :

-- linux-redhat6-x86_64 / intel@15.0.4 --------------------------
w33hrej libelf@0.8.13%intel


==> Do you want to proceed? [y/n] y
==> Successfully uninstalled libelf@0.8.13%intel@15.0.4 arch=linux-redhat6-x86_64-w33hrej



$ spack find -lf libelf
==> 5 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
ipggckv libelf@0.8.12%gcc

vrv2ttb libelf@0.8.12%gcc cppflags="-O3"

csrt4qx libelf@0.8.13%gcc


-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
4blbe3q libelf@0.8.12%intel

7wgp32x libelf@0.8.13%intel

We can uninstall packages by referring only to their hash.

We can use either -f (force) or -d (remove dependents as well) to remove packages that are required by another installed package.

$ spack uninstall /4blb
==> Error: Will not uninstall libelf@0.8.12%intel@16.0.3-4blbe3q

The following packages depend on it:
-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
csruprg libdwarf@20160507%intel


==> Error: You can use spack uninstall --dependents to uninstall these dependencies as well
$ spack uninstall -d /4blb
==> The following packages will be uninstalled :

-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
csruprg libdwarf@20160507%intel

4blbe3q libelf@0.8.12%intel


==> Do you want to proceed? [y/n] y
==> Successfully uninstalled libdwarf@20160507%intel@16.0.3 arch=linux-redhat6-x86_64-csruprg
==> Successfully uninstalled libelf@0.8.12%intel@16.0.3 arch=linux-redhat6-x86_64-4blbe3q

Spack will not uninstall packages that are not sufficiently specified. The -a (all) flag can be used to uninstall multiple packages at once.

$ spack uninstall trilinos
==> Error: trilinos matches multiple packages:

-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
ffwrpxn trilinos@12.8.1%gcc+boost~debug+hdf5+hypre+metis+mumps~python+shared+suite-sparse+superlu-dist

uvd6dfd trilinos@12.8.1%gcc+boost~debug+hdf5+hypre+metis+mumps~python+shared+suite-sparse+superlu-dist


==> Error: You can either:
    a) Use a more specific spec, or
    b) use spack uninstall -a to uninstall ALL matching specs.



$ spack uninstall /ffwr
==> The following packages will be uninstalled :

-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
ffwrpxn trilinos@12.8.1%gcc+boost~debug+hdf5+hypre+metis+mumps~python+shared+suite-sparse+superlu-dist


==> Do you want to proceed? [y/n] y
==> Successfully uninstalled trilinos@12.8.1%gcc@4.4.7+boost~debug+hdf5+hypre+metis+mumps~python+shared+suite-sparse+superlu-dist arch=linux-redhat6-x86_64-ffwrpxn

Advanced spack find Usage

We will go over some additional uses for the spack find command not already covered in the Installing Spack and Uninstalling Packages sections.

The spack find command can accept what we call “anonymous specs.” These are expressions in spec syntax that do not contain a package name. For example, spack find %intel will return every package built with the intel compiler, and spack find cppflags="-O3" will return every package which was built with cppflags="-O3".

$ spack find %intel
==> 1 installed packages.
-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
libelf@0.8.13



$ spack find cppflags="-O3"
==> 1 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
libelf@0.8.12

The find command can also show which packages were installed explicitly (rather than pulled in as a dependency) using the -e flag. The -E flag shows implicit installs only. The find command can also show the path to which a spack package was installed using the -p command.

$ spack find -pe
==> 10 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
    hdf5@1.10.0-patch1  ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-twppaioxqn6lti4grgopnmhwcq3h2rpw
    hdf5@1.10.0-patch1  ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-j36yfw25i6gdd3q4vwlupgkpwic4ua6m
    hdf5@1.10.0-patch1  ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/hdf5-1.10.0-patch1-ezvtnox35albuaxqryuondweyjgeo6es
    libdwarf@20160507   ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libdwarf-20160507-dtg3tgnp7htccoly26gduqlrgvnwcp5t
    libdwarf@20160507   ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libdwarf-20160507-yfx6p3g3rkmqvcqbmtb34o6pln7pqvcz
    libelf@0.8.12       ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.12-ipggckv6i7h44iryzfa4dwdela32a7fy
    libelf@0.8.12       ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.12-vrv2ttbd34xlfoxy4jwt6qsjrcbalmmw
    libelf@0.8.13       ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/libelf-0.8.13-csrt4qxfkhjgn5xg3zjpkir7xdnszl2a
    trilinos@12.8.1     ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/trilinos-12.8.1-uvd6dfd7x4uyvck4awo3r3frudihn4ar

-- linux-redhat6-x86_64 / intel@16.0.3 --------------------------
    libelf@0.8.13  ~/spack/opt/spack/linux-redhat6-x86_64/intel-16.0.3/libelf-0.8.13-7wgp32xksatkvw2tbssmehw2t5tnxndj

Customizing Compilers

Spack manages a list of available compilers on the system, detected automatically from from the user’s PATH variable. The spack compilers command is an alias for the command spack compiler list.

$ spack compilers
==> Available compilers
-- gcc ----------------------------------------------------------
gcc@4.4.7

-- intel --------------------------------------------------------
intel@16.0.3  intel@15.0.1  intel@14.0.0  intel@12.1.3  intel@10.0
intel@16.0.2  intel@15.0.0  intel@13.1.1  intel@12.1.2  intel@9.1
intel@16.0.1  intel@14.0.4  intel@13.1.0  intel@12.1.0
intel@16.0.0  intel@14.0.3  intel@13.0.1  intel@12.0.4
intel@15.0.4  intel@14.0.2  intel@13.0.0  intel@11.1
intel@15.0.3  intel@14.0.1  intel@12.1.5  intel@10.1

-- pgi ----------------------------------------------------------
pgi@16.5-0   pgi@15.7-0   pgi@14.7-0   pgi@13.2-0  pgi@11.10-0  pgi@9.0-4
pgi@16.3-0   pgi@15.5-0   pgi@14.3-0   pgi@13.1-1  pgi@11.1-0   pgi@8.0-1
pgi@16.1-0   pgi@15.1-0   pgi@13.10-0  pgi@12.8-0  pgi@10.9-0   pgi@7.1-3
pgi@15.10-0  pgi@14.10-0  pgi@13.6-0   pgi@12.1-0  pgi@10.2-0   pgi@7.0-6

The compilers are maintained in a YAML file that can be hand-edited for special cases. Spack also has tools to add compilers, and compilers built with Spack can be added to the configuration.

$ spack install --fake gcc@6.1.0
==> Installing gcc
==> gmp is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gmp-6.1.1-uwn4gfdtq3sywy5uf4f7znrh66oybikf
==> Installing isl
==> gmp is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gmp-6.1.1-uwn4gfdtq3sywy5uf4f7znrh66oybikf
==> Building isl [Package]
==> Successfully installed isl
  Fetch: .  Build: 0.19s.  Total: 0.19s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/isl-0.14-hs2w7mjjjaakkmbbv5yvfqf7yyzhorl6
==> Installing mpc
==> gmp is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gmp-6.1.1-uwn4gfdtq3sywy5uf4f7znrh66oybikf
==> Installing mpfr
==> gmp is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gmp-6.1.1-uwn4gfdtq3sywy5uf4f7znrh66oybikf
==> Building mpfr [Package]
==> Successfully installed mpfr
  Fetch: .  Build: 0.17s.  Total: 0.17s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpfr-3.1.4-7kt5ij437khredfq4bvnyu22t3fmtfvt
==> Building mpc [Package]
==> Successfully installed mpc
  Fetch: .  Build: 0.28s.  Total: 0.28s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpc-1.0.3-g5taq6lt3zuy5l2jtggi5lctxnl4la5u
==> Installing binutils
==> m4 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> Installing bison
==> m4 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> Building bison [Package]
==> Successfully installed bison
  Fetch: .  Build: 0.12s.  Total: 0.12s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/bison-3.0.4-hkhfysfvq5l6rsns67g2htmkpxauvnwa
==> Installing flex
==> m4 is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/m4-1.4.17-qijdzvhjyybrtwbqm73vykhmkaqro3je
==> bison is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/bison-3.0.4-hkhfysfvq5l6rsns67g2htmkpxauvnwa
==> Building flex [Package]
==> Successfully installed flex
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/flex-2.6.0-qd6d73rdfrozdrsdpimvl4tj7d5ps7qg
==> Building binutils [Package]
==> Successfully installed binutils
  Fetch: .  Build: 0.11s.  Total: 0.11s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/binutils-2.27-iq2hry3gvaxszmwwbnll7njgdgaek56o
==> mpfr is already installed in ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/mpfr-3.1.4-7kt5ij437khredfq4bvnyu22t3fmtfvt
==> Building gcc [Package]
==> Successfully installed gcc
  Fetch: .  Build: 0.66s.  Total: 0.66s.
[+] ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gcc-6.1.0-j5576zbsot2ydljlthjzhsirsesnogvh



$ spack find -p gcc
==> 1 installed packages.
-- linux-redhat6-x86_64 / gcc@4.4.7 -----------------------------
    gcc@6.1.0  ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gcc-6.1.0-j5576zbsot2ydljlthjzhsirsesnogvh

If we had done a “real” install of gcc, we could add it to our configuration now using the spack compiler add command, but we would also be waiting for it to install. If we run the command now, it will return no new compilers.

$ spack compiler add ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gcc-6.1.0-j5576zbsot2ydljlthjzhsirsesnogvh/bin
==> Found no new compilers

If we had done a real install, the output would have been as follows:

$ spack compiler add ~/spack/opt/spack/linux-redhat6-x86_64/gcc-4.4.7/gcc-6.1.0-j5576zbsot2ydljlthjzhsirsesnogvh/bin
==> Added 1 new compiler to ~/.spack/linux/compilers.yaml
    gcc@6.1.0