Modules (modules.yaml)

The use of module systems to manage user environment in a controlled way is a common practice at HPC centers that is often embraced also by individual programmers on their development machines. To support this common practice Spack integrates with Environment Modules and Lmod by providing post-install hooks that generate module files and commands to manipulate them.

Modules are one of several ways you can use Spack packages. For other options that may fit your use case better, you should also look at spack load and environments.

Using module files via Spack

If you have installed a supported module system you should be able to run module avail to see what module files have been installed. Here is sample output of those programs, showing lots of installed packages:

$ module avail

--------------------------------------------------------------- ~/spack/share/spack/modules/linux-ubuntu14-x86_64 ---------------------------------------------------------------
autoconf/2.69-gcc-4.8-qextxkq       hwloc/1.11.6-gcc-6.3.0-akcisez             m4/1.4.18-gcc-4.8-ev2znoc                   openblas/0.2.19-gcc-6.3.0-dhkmed6        py-setuptools/34.2.0-gcc-6.3.0-fadur4s
automake/1.15-gcc-4.8-maqvukj       isl/0.18-gcc-4.8-afi6taq                   m4/1.4.18-gcc-6.3.0-uppywnz                 openmpi/2.1.0-gcc-6.3.0-go2s4z5          py-six/1.10.0-gcc-6.3.0-p4dhkaw
binutils/2.28-gcc-4.8-5s7c6rs       libiconv/1.15-gcc-4.8-at46wg3              mawk/1.3.4-gcc-4.8-acjez57                  openssl/1.0.2k-gcc-4.8-dkls5tk           python/2.7.13-gcc-6.3.0-tyehea7
bison/3.0.4-gcc-4.8-ek4luo5         libpciaccess/0.13.4-gcc-6.3.0-gmufnvh      mawk/1.3.4-gcc-6.3.0-ostdoms                openssl/1.0.2k-gcc-6.3.0-gxgr5or         readline/7.0-gcc-4.8-xhufqhn
bzip2/1.0.6-gcc-4.8-iffrxzn         libsigsegv/2.11-gcc-4.8-pp2cvte            mpc/1.0.3-gcc-4.8-g5mztc5                   pcre/8.40-gcc-4.8-r5pbrxb                readline/7.0-gcc-6.3.0-zzcyicg
bzip2/1.0.6-gcc-6.3.0-bequudr       libsigsegv/2.11-gcc-6.3.0-7enifnh          mpfr/3.1.5-gcc-4.8-o7xm7az                  perl/5.24.1-gcc-4.8-dg5j65u              sqlite/3.8.5-gcc-6.3.0-6zoruzj
cmake/3.7.2-gcc-6.3.0-fowuuby       libtool/2.4.6-gcc-4.8-7a523za              mpich/3.2-gcc-6.3.0-dmvd3aw                 perl/5.24.1-gcc-6.3.0-6uzkpt6            tar/1.29-gcc-4.8-wse2ass
curl/7.53.1-gcc-4.8-3fz46n6         libtool/2.4.6-gcc-6.3.0-n7zmbzt            ncurses/6.0-gcc-4.8-dcpe7ia                 pkg-config/0.29.2-gcc-4.8-ib33t75        tcl/8.6.6-gcc-4.8-tfxzqbr
expat/2.2.0-gcc-4.8-mrv6bd4         libxml2/2.9.4-gcc-4.8-ryzxnsu              ncurses/6.0-gcc-6.3.0-ucbhcdy               pkg-config/0.29.2-gcc-6.3.0-jpgubk3      util-macros/1.19.1-gcc-6.3.0-xorz2x2
flex/2.6.3-gcc-4.8-yf345oo          libxml2/2.9.4-gcc-6.3.0-rltzsdh            netlib-lapack/3.6.1-gcc-6.3.0-js33dog       py-appdirs/1.4.0-gcc-6.3.0-jxawmw7       xz/5.2.3-gcc-4.8-mew4log
gcc/6.3.0-gcc-4.8-24puqve           lmod/7.4.1-gcc-4.8-je4srhr                 netlib-scalapack/2.0.2-gcc-6.3.0-5aidk4l    py-numpy/1.12.0-gcc-6.3.0-oemmoeu        xz/5.2.3-gcc-6.3.0-3vqeuvb
gettext/0.19.8.1-gcc-4.8-yymghlh    lua/5.3.4-gcc-4.8-im75yaz                  netlib-scalapack/2.0.2-gcc-6.3.0-hjsemcn    py-packaging/16.8-gcc-6.3.0-i2n3dtl      zip/3.0-gcc-4.8-rwar22d
gmp/6.1.2-gcc-4.8-5ub2wu5           lua-luafilesystem/1_6_3-gcc-4.8-wkey3nl    netlib-scalapack/2.0.2-gcc-6.3.0-jva724b    py-pyparsing/2.1.10-gcc-6.3.0-tbo6gmw    zlib/1.2.11-gcc-4.8-pgxsxv7
help2man/1.47.4-gcc-4.8-kcnqmau     lua-luaposix/33.4.0-gcc-4.8-mdod2ry        netlib-scalapack/2.0.2-gcc-6.3.0-rgqfr6d    py-scipy/0.19.0-gcc-6.3.0-kr7nat4        zlib/1.2.11-gcc-6.3.0-7cqp6cj

The names should look familiar, as they resemble the output from spack find. For example, you could type the following command to load the cmake module:

$ module load cmake/3.7.2-gcc-6.3.0-fowuuby

Neither of these is particularly pretty, easy to remember, or easy to type. Luckily, Spack offers many facilities for customizing the module scheme used at your site.

Module file customization

Module files are generated by post-install hooks after the successful installation of a package.

Note

Spack only generates modulefiles when a package is installed. If you attempt to install a package and it is already installed, Spack will not regenerate modulefiles for the package. This may lead to inconsistent modulefiles if the Spack module configuration has changed since the package was installed, either by editing a file or changing scopes or environments.

Later in this section there is a subsection on regenerating modules that will allow you to bring your modules to a consistent state.

The table below summarizes the essential information associated with the different file formats that can be generated by Spack:

	Hook name	Default root directory	Default template file	Compatible tools
Tcl - Non-Hierarchical	tcl	share/spack/modules	share/spack/templates/modules/modulefile.tcl	Env. Modules/Lmod
Lua - Hierarchical	lmod	share/spack/lmod	share/spack/templates/modules/modulefile.lua	Lmod

Spack ships with sensible defaults for the generation of module files, but you can customize many aspects of it to accommodate package or site specific needs. In general you can override or extend the default behavior by:

1. overriding certain callback APIs in the Python packages

2. writing specific rules in the modules.yaml configuration file

3. writing your own templates to override or extend the defaults

The former method let you express changes in the run-time environment that are needed to use the installed software properly, e.g. injecting variables from language interpreters into their extensions. The latter two instead permit to fine tune the filesystem layout, content and creation of module files to meet site specific conventions.

Override API calls in package.py

There are two methods that you can override in any package.py to affect the content of the module files generated by Spack. The first one:

def setup_run_environment(self, env):
    pass

can alter the content of the module file associated with the same package where it is overridden. The second method:

def setup_dependent_run_environment(self, env, dependent_spec):
    pass

can instead inject run-time environment modifications in the module files of packages that depend on it. In both cases you need to fill env with the desired list of environment modifications.

The r package and callback APIs

An example in which it is crucial to override both methods is given by the r package. This package installs libraries and headers in non-standard locations and it is possible to prepend the appropriate directory to the corresponding environment variables:

LD_LIBRARY_PATH	self.prefix/rlib/R/lib
PKG_CONFIG_PATH	self.prefix/rlib/pkgconfig

with the following snippet:

    def setup_run_environment(self, env):
        env.prepend_path("LD_LIBRARY_PATH", join_path(self.prefix, "rlib", "R", "lib"))
        env.prepend_path("PKG_CONFIG_PATH", join_path(self.prefix, "rlib", "pkgconfig"))
        env.set("R_HOME", join_path(self.prefix, "rlib", "R"))

        if "+rmath" in self.spec:
            env.prepend_path("LD_LIBRARY_PATH", join_path(self.prefix, "rlib"))

The r package also knows which environment variable should be modified to make language extensions provided by other packages available, and modifies it appropriately in the override of the second method:

    def setup_dependent_run_environment(self, env, dependent_spec):
        # For run time environment set only the path for dependent_spec and
        # prepend it to R_LIBS
        env.set("R_HOME", join_path(self.prefix, "rlib", "R"))
        if dependent_spec.package.extends(self.spec):
            env.prepend_path("R_LIBS", join_path(dependent_spec.prefix, self.r_lib_dir))

Write a configuration file

The configuration files that control module generation behavior are named modules.yaml. The default configuration:

# -------------------------------------------------------------------------
# This is the default configuration for Spack's module file generation.
#
# Settings here are versioned with Spack and are intended to provide
# sensible defaults out of the box. Spack maintainers should edit this
# file to keep it current.
#
# Users can override these settings by editing the following files.
#
# Per-spack-instance settings (overrides defaults):
#   $SPACK_ROOT/etc/spack/modules.yaml
#
# Per-user settings (overrides default and site settings):
#   ~/.spack/modules.yaml
# -------------------------------------------------------------------------
modules:
  # This maps paths in the package install prefix to environment variables
  # they should be added to. For example, <prefix>/bin should be in PATH.
  prefix_inspections:
    ./bin:
      - PATH
    ./man:
      - MANPATH
    ./share/man:
      - MANPATH
    ./share/aclocal:
      - ACLOCAL_PATH
    ./lib/pkgconfig:
      - PKG_CONFIG_PATH
    ./lib64/pkgconfig:
      - PKG_CONFIG_PATH
    ./share/pkgconfig:
      - PKG_CONFIG_PATH
    ./:
      - CMAKE_PREFIX_PATH

  # These are configurations for the module set named "default"
  default:
    # Where to install modules
    roots:
     tcl:    $spack/share/spack/modules
     lmod:   $spack/share/spack/lmod
    # What type of modules to use ("tcl" and/or "lmod")
    enable: []

    tcl:
      all:
        autoload: direct

    # Default configurations if lmod is enabled
    lmod:
      all:
        autoload: direct
      hierarchy:
        - mpi

activates the hooks to generate tcl module files and inspects the installation folder of each package for the presence of a set of subdirectories (bin, man, share/man, etc.). If any is found its full path is prepended to the environment variables listed below the folder name.

Spack modules can be configured for multiple module sets. The default module set is named default. All Spack commands which operate on modules default to apply the default module set, but can be applied to any module set in the configuration.

Changing the modules root

As shown in the table above, the default module root for lmod is $spack/share/spack/lmod and the default root for tcl is $spack/share/spack/modules. This can be overridden for any module set by changing the roots key of the configuration.

modules:
  default:
    roots:
      tcl: /path/to/install/tcl/modules
  my_custom_lmod_modules:
    roots:
      lmod: /path/to/install/custom/lmod/modules
      ...

This configuration will create two module sets. The default module set will install its tcl modules to /path/to/install/tcl/modules (and still install its lmod modules, if any, to the default location). The set my_custom_lmod_modules will install its lmod modules to /path/to/install/custom/lmod/modules (and still install its tcl modules, if any, to the default location).

By default, an architecture-specific directory is added to the root directory. A module set may override that behavior by setting the arch_folder config value to False.

modules:
  default:
    roots:
      tcl: /path/to/install/tcl/modules
    arch_folder: false

Obviously, having multiple module sets install modules to the default location could be confusing to users of your modules. In the next section, we will discuss enabling and disabling module types (module file generators) for each module set.

Activate other hooks

Any other module file generator shipped with Spack can be activated adding it to the list under the enable key in the module file. Currently the only generator that is not active by default is lmod, which produces hierarchical lua module files.

Each module system can then be configured separately. In fact, you should list configuration options that affect a particular type of module files under a top level key corresponding to the generator being customized:

modules:
  default:
    enable:
      - tcl
      - lmod
    tcl:
      # contains environment modules specific customizations
    lmod:
      # contains lmod specific customizations

In general, the configuration options that you can use in modules.yaml will either change the layout of the module files on the filesystem, or they will affect their content. For the latter point it is possible to use anonymous specs to fine tune the set of packages on which the modifications should be applied.

Selection by anonymous specs

In the configuration file you can use anonymous specs (i.e. specs that are not required to have a root package and are thus used just to express constraints) to apply certain modifications on a selected set of the installed software. For instance, in the snippet below:

modules:
  default:
    tcl:
      # The keyword `all` selects every package
      all:
        environment:
          set:
            BAR: 'bar'
      # This anonymous spec selects any package that
      # depends on mpi. The double colon at the
      # end clears the set of rules that matched so far.
      ^mpi::
        environment:
          prepend_path:
            PATH: '{^mpi.prefix}/bin'
          set:
            BAR: 'baz'
      # Selects any zlib package
      zlib:
        environment:
          prepend_path:
            LD_LIBRARY_PATH: 'foo'
      # Selects zlib compiled with gcc@4.8
      zlib%gcc@4.8:
        environment:
          unset:
          - FOOBAR

you are instructing Spack to set the environment variable BAR=bar for every module, unless the associated spec satisfies the abstract dependency ^mpi in which case BAR=baz, and the directory containing the respective MPI executables is prepended to the PATH variable. In addition in any spec that satisfies zlib the value foo will be prepended to LD_LIBRARY_PATH and in any spec that satisfies zlib%gcc@4.8 the variable FOOBAR will be unset.

Note

Order does matter

The modifications associated with the all keyword are always evaluated first, no matter where they appear in the configuration file. All the other spec constraints are instead evaluated top to bottom.

Exclude or include specific module files

You can use anonymous specs also to prevent module files from being written or to force them to be written. Consider the case where you want to hide from users all the boilerplate software that you had to build in order to bootstrap a new compiler. Suppose for instance that gcc@4.4.7 is the compiler provided by your system. If you write a configuration file like:

modules:
  default:
    tcl:
      include: ['gcc', 'llvm']  # include will have precedence over exclude
      exclude: ['%gcc@4.4.7']   # Assuming gcc@4.4.7 is the system compiler

you will prevent the generation of module files for any package that is compiled with gcc@4.4.7, with the only exception of any gcc or any llvm installation.

Customize the naming of modules

The names of environment modules generated by spack are not always easy to fully comprehend due to the long hash in the name. There are three module configuration options to help with that. The first is a global setting to adjust the hash length. It can be set anywhere from 0 to 32 and has a default length of 7. This is the representation of the hash in the module file name and does not affect the size of the package hash. Be aware that the smaller the hash length the more likely naming conflicts will occur. The following snippet shows how to set hash length in the module file names:

modules:
  default:
    tcl:
      hash_length: 7

To help make module names more readable, and to help alleviate name conflicts with a short hash, one can use the suffixes option in the modules configuration file. This option will add strings to modules that match a spec. For instance, the following config options,

modules:
  default:
    tcl:
      all:
        suffixes:
          ^python@2.7.12: 'python-2.7.12'
          ^openblas: 'openblas'

will add a python-2.7.12 version string to any packages compiled with python matching the spec, python@2.7.12. This is useful to know which version of python a set of python extensions is associated with. Likewise, the openblas string is attached to any program that has openblas in the spec, most likely via the +blas variant specification.

The most heavyweight solution to module naming is to change the entire naming convention for module files. This uses the projections format covered in View Projections.

modules:
  default:
    tcl:
      projections:
        all: '{name}/{version}-{compiler.name}-{compiler.version}-module'
        ^mpi: '{name}/{version}-{^mpi.name}-{^mpi.version}-{compiler.name}-{compiler.version}-module'

will create module files that are nested in directories by package name, contain the version and compiler name and version, and have the word module before the hash for all specs that do not depend on mpi, and will have the same information plus the MPI implementation name and version for all packages that depend on mpi.

When specifying module names by projection for Lmod modules, we recommend NOT including names of dependencies (e.g., MPI, compilers) that are already in the Lmod hierarchy.

Note

Tcl and Lua modules also allow for explicit conflicts between modulefiles.

modules:
  default:
    enable:
      - tcl
    tcl:
      projections:
        all: '{name}/{version}-{compiler.name}-{compiler.version}'
      all:
        conflict:
          - '{name}'
          - 'intel/14.0.1'

will create module files that will conflict with intel/14.0.1 and with the base directory of the same module, effectively preventing the possibility to load two or more versions of the same software at the same time. The tokens that are available for use in this directive are the same understood by the format() method.

For Lmod and Environment Modules versions prior 4.2, it is important to express the conflict on both modulefiles conflicting with each other.

Note

Lmod hierarchical module files

When lmod is activated Spack will generate a set of hierarchical lua module files that are understood by Lmod. The hierarchy will always contain the two layers Core / Compiler but can be further extended to any of the virtual dependencies present in Spack. A case that could be useful in practice is for instance:

modules:
  default:
    enable:
      - lmod
    lmod:
      core_compilers:
        - 'gcc@4.8'
      core_specs:
        - 'python'
      hierarchy:
        - 'mpi'
        - 'lapack'

that will generate a hierarchy in which the lapack and mpi layer can be switched independently. This allows a site to build the same libraries or applications against different implementations of mpi and lapack, and let Lmod switch safely from one to the other.

All packages built with a compiler in core_compilers and all packages that satisfy a spec in core_specs will be put in the Core hierarchy of the lua modules.

Warning

Consistency of Core packages

The user is responsible for maintining consistency among core packages, as core_specs bypasses the hierarchy that allows Lmod to safely switch between coherent software stacks.

Warning

Deep hierarchies and lmod spider

For hierarchies that are deeper than three layers lmod spider may have some issues. See this discussion on the Lmod project.

Select default modules

By default, when multiple modules of the same name share a directory, the highest version number will be the default module. This behavior of the module command can be overridden with a symlink named default to the desired default module. If you wish to configure default modules with Spack, add a defaults key to your modules configuration:

modules:
  my-module-set:
    tcl:
      defaults:
      - gcc@10.2.1
      - hdf5@1.2.10+mpi+hl%gcc

These defaults may be arbitrarily specific. For any package that satisfies a default, Spack will generate the module file in the appropriate path, and will generate a default symlink to the module file as well.

Warning

If Spack is configured to generate multiple default packages in the same directory, the last modulefile to be generated will be the default module.

Customize environment modifications

You can control which prefixes in a Spack package are added to environment variables with the prefix_inspections section; this section maps relative prefixes to the list of environment variables which should be updated with those prefixes.

The prefix_inspections configuration is different from other settings in that a prefix_inspections configuration at the modules level of the configuration file applies to all module sets. This allows users to make general overrides to the default inspections and customize them per-module-set.

modules:
  prefix_inspections:
    ./bin:
      - PATH
    ./man:
      - MANPATH
    ./:
      - CMAKE_PREFIX_PATH

Prefix inspections are only applied if the relative path inside the installation prefix exists. In this case, for a Spack package foo installed to /spack/prefix/foo, if foo installs executables to bin but no manpages in man, the generated module file for foo would update PATH to contain /spack/prefix/foo/bin and CMAKE_PREFIX_PATH to contain /spack/prefix/foo, but would not update MANPATH.

The default list of environment variables in this config section includes PATH, MANPATH, ACLOCAL_PATH, PKG_CONFIG_PATH and CMAKE_PREFIX_PATH, as well as DYLD_FALLBACK_LIBRARY_PATH on macOS. On Linux however, the corresponding LD_LIBRARY_PATH variable is not set, because it affects the behavior of system executables too.

Note

In general, the LD_LIBRARY_PATH variable is not required when using packages built with Spack, thanks to the use of RPATH. Some packages may still need the variable, which is best handled on a per-package basis instead of globally, as explained in Override API calls in package.py.

There is a special case for prefix inspections relative to environment views. If all of the following conditions hold for a module set configuration:

1. The configuration is for an environment and will never be applied outside the environment,

2. The environment in question is configured to use a view,

3. The environment view is configured with a projection that ensures every package is linked to a unique directory,

then the module set may be configured to create modules relative to the environment view. This is specified by the use_view configuration option in the module set. If True, the module set is constructed relative to the default view of the environment. Otherwise, the value must be the name of the environment view relative to which to construct modules, or False-ish to disable the feature explicitly (the default is False).

If the use_view value is set in the config, then the prefix inspections for the package are done relative to the package’s path in the view.

spack:
  modules:
    view_relative_modules:
      use_view: my_view
    prefix_inspections:
      ./bin:
        - PATH
  view:
    my_view:
      projections:
        root: /path/to/my/view
        all:  '{name}-{hash}'

The spack key is relevant to environment configuration, and the view key is discussed in detail in the section on Configuring environment views. With this configuration the generated module for package foo would set PATH to include /path/to/my/view/foo-<hash>/bin instead of /spack/prefix/foo/bin.

The use_view option is useful when deploying a large software stack to users who are likely to inspect the modules to find full paths to software, when it is desirable to present the users with a simpler set of paths than those generated by the Spack install tree.

Filter out environment modifications

Modifications to certain environment variables in module files are there by default, for instance because they are generated by prefix inspections. If you want to prevent modifications to some environment variables, you can do so by using the exclude_env_vars:

modules:
  default:
    tcl:
      all:
        filter:
          # Exclude changes to any of these variables
          exclude_env_vars: ['CPATH', 'LIBRARY_PATH']

The configuration above will generate module files that will not contain modifications to either CPATH or LIBRARY_PATH.

Autoload dependencies

Often it is required for a module to have its (transient) dependencies loaded as well. One example where this is useful is when one package needs to use executables provided by its dependency; when the dependency is autoloaded, the executable will be in the PATH. Similarly for scripting languages such as Python, packages and their dependencies have to be loaded together.

Autoloading is enabled by default for Lmod and Environment Modules. The former has builtin support for through the depends_on function. The latter uses module load statement to load and track dependencies.

Autoloading can also be enabled conditionally:

modules:
  default:
    tcl:
      all:
        autoload: none
      ^python:
        autoload: direct

The configuration file above will produce module files that will load their direct dependencies if the package installed depends on python. The allowed values for the autoload statement are either none, direct or all.

Note

Tcl prerequisites

In the tcl section of the configuration file it is possible to use the prerequisites directive that accepts the same values as autoload. It will produce module files that have a prereq statement, which autoloads dependencies on Environment Modules when its auto_handling configuration option is enabled. If Environment Modules is installed with Spack, auto_handling is enabled by default starting version 4.2. Otherwise it is enabled by default since version 5.0.

Maintaining Module Files

Each type of module file has a command with the same name associated with it. The actions these commands permit are usually associated with the maintenance of a production environment. Here’s, for instance, a sample of the features of the spack module tcl command:

$ spack module tcl --help
usage: spack module tcl [-h] [-n MODULE_SET_NAME] SUBCOMMAND ...

positional arguments:
  SUBCOMMAND
    refresh             regenerate module files
    find                find module files for packages
    rm                  remove module files
    loads               prompt the list of modules associated with a constraint
    setdefault          set the default module file for a package

options:
  -h, --help            show this help message and exit
  -n MODULE_SET_NAME, --name MODULE_SET_NAME
                        named module set to use from modules configuration

Refresh the set of modules

The subcommand that regenerates module files to update their content or their layout is refresh:

$ spack module tcl refresh --help
usage: spack module tcl refresh [-hy] [--delete-tree] [--upstream-modules] ...

positional arguments:
  installed_specs     constraint to select a subset of installed packages

options:
  --delete-tree       delete the module file tree before refresh
  --upstream-modules  generate modules for packages installed upstream
  -h, --help          show this help message and exit
  -y, --yes-to-all    assume "yes" is the answer to every confirmation request

A set of packages can be selected using anonymous specs for the optional constraint positional argument. Optionally the entire tree can be deleted before regeneration if the change in layout is radical.

Delete module files

If instead what you need is just to delete a few module files, then the right subcommand is rm:

$ spack module tcl rm --help
usage: spack module tcl rm [-hy] ...

positional arguments:
  installed_specs   constraint to select a subset of installed packages

options:
  -h, --help        show this help message and exit
  -y, --yes-to-all  assume "yes" is the answer to every confirmation request

Note

We care about your module files!

Every modification done on modules that are already existing will ask for a confirmation by default. If the command is used in a script it is possible though to pass the -y argument, that will skip this safety measure.

Using Spack modules in shell scripts

The easiest To enable additional Spack commands for loading and unloading module files, and to add the correct path to MODULEPATH, you need to source the appropriate setup file. Assuming Spack is installed in $SPACK_ROOT, run the appropriate command for your shell:

# For bash/zsh/sh
$ . $SPACK_ROOT/share/spack/setup-env.sh

# For tcsh/csh
$ source $SPACK_ROOT/share/spack/setup-env.csh

# For fish
$ . $SPACK_ROOT/share/spack/setup-env.fish

If you want to have Spack’s shell support available on the command line at any login you can put this source line in one of the files that are sourced at startup (like .profile, .bashrc or .cshrc). Be aware that the shell startup time may increase slightly as a result.

spack module tcl loads

In some cases, it is desirable to use a Spack-generated module, rather than relying on Spack’s built-in user-environment modification capabilities. To translate a spec into a module name, use spack module tcl loads or spack module lmod loads depending on the module system desired.

To load not just a module, but also all the modules it depends on, use the --dependencies option. This is not required for most modules because Spack builds binaries with RPATH support. However, not all packages use RPATH to find their dependencies: this can be true in particular for Python extensions, which are currently not built with RPATH.

Scripts to load modules recursively may be made with the command:

$ spack module tcl loads --dependencies <spec>

An equivalent alternative using process substitution is:

$ source <( spack module tcl loads --dependencies <spec> )

Module Commands for Shell Scripts

Although Spack is flexible, the module command is much faster. This could become an issue when emitting a series of spack load commands inside a shell script. By adding the --dependencies flag, spack module tcl loads may also be used to generate code that can be cut-and-pasted into a shell script. For example:

$ spack module tcl loads --dependencies py-numpy git
# bzip2@1.0.6%gcc@4.9.3=linux-x86_64
module load bzip2/1.0.6-gcc-4.9.3-ktnrhkrmbbtlvnagfatrarzjojmkvzsx
# ncurses@6.0%gcc@4.9.3=linux-x86_64
module load ncurses/6.0-gcc-4.9.3-kaazyneh3bjkfnalunchyqtygoe2mncv
# zlib@1.2.8%gcc@4.9.3=linux-x86_64
module load zlib/1.2.8-gcc-4.9.3-v3ufwaahjnviyvgjcelo36nywx2ufj7z
# sqlite@3.8.5%gcc@4.9.3=linux-x86_64
module load sqlite/3.8.5-gcc-4.9.3-a3eediswgd5f3rmto7g3szoew5nhehbr
# readline@6.3%gcc@4.9.3=linux-x86_64
module load readline/6.3-gcc-4.9.3-se6r3lsycrwxyhreg4lqirp6xixxejh3
# python@3.5.1%gcc@4.9.3=linux-x86_64
module load python/3.5.1-gcc-4.9.3-5q5rsrtjld4u6jiicuvtnx52m7tfhegi
# py-setuptools@20.5%gcc@4.9.3=linux-x86_64
module load py-setuptools/20.5-gcc-4.9.3-4qr2suj6p6glepnedmwhl4f62x64wxw2
# py-nose@1.3.7%gcc@4.9.3=linux-x86_64
module load py-nose/1.3.7-gcc-4.9.3-pwhtjw2dvdvfzjwuuztkzr7b4l6zepli
# openblas@0.2.17%gcc@4.9.3+shared=linux-x86_64
module load openblas/0.2.17-gcc-4.9.3-pw6rmlom7apfsnjtzfttyayzc7nx5e7y
# py-numpy@1.11.0%gcc@4.9.3+blas+lapack=linux-x86_64
module load py-numpy/1.11.0-gcc-4.9.3-mulodttw5pcyjufva4htsktwty4qd52r
# curl@7.47.1%gcc@4.9.3=linux-x86_64
module load curl/7.47.1-gcc-4.9.3-ohz3fwsepm3b462p5lnaquv7op7naqbi
# autoconf@2.69%gcc@4.9.3=linux-x86_64
module load autoconf/2.69-gcc-4.9.3-bkibjqhgqm5e3o423ogfv2y3o6h2uoq4
# cmake@3.5.0%gcc@4.9.3~doc+ncurses+openssl~qt=linux-x86_64
module load cmake/3.5.0-gcc-4.9.3-x7xnsklmgwla3ubfgzppamtbqk5rwn7t
# expat@2.1.0%gcc@4.9.3=linux-x86_64
module load expat/2.1.0-gcc-4.9.3-6pkz2ucnk2e62imwakejjvbv6egncppd
# git@2.8.0-rc2%gcc@4.9.3+curl+expat=linux-x86_64
module load git/2.8.0-rc2-gcc-4.9.3-3bib4hqtnv5xjjoq5ugt3inblt4xrgkd

The script may be further edited by removing unnecessary modules.

Module Prefixes

On some systems, modules are automatically prefixed with a certain string; spack module tcl loads needs to know about that prefix when it issues module load commands. Add the --prefix option to your spack module tcl loads commands if this is necessary.

For example, consider the following on one system:

$ module avail
linux-SuSE11-x86_64/antlr/2.7.7-gcc-5.3.0-bdpl46y

$ spack module tcl loads antlr    # WRONG!
# antlr@2.7.7%gcc@5.3.0~csharp+cxx~java~python arch=linux-SuSE11-x86_64
module load antlr/2.7.7-gcc-5.3.0-bdpl46y

$ spack module tcl loads --prefix linux-SuSE11-x86_64/ antlr
# antlr@2.7.7%gcc@5.3.0~csharp+cxx~java~python arch=linux-SuSE11-x86_64
module load linux-SuSE11-x86_64/antlr/2.7.7-gcc-5.3.0-bdpl46y