Configuration Legacy

Legacy configuration is currently deprecated!

If you are a new user of EasyBuild you can safely ignore everything below this line, refer instead to Configuring EasyBuild.

Porting from legacy configuration style

In EasyBuild v1.x, a couple of configuration options, other than the standard ones aligned with variables, are available that follow the legacy configuration style, including:

  • the -C and --config command line arguments ( use --configfiles instead )
  • the $EASYBUILDCONFIG environment variable ( use $EASYBUILD_CONFIGFILES instead )
  • the default path $HOME/.easybuild/ ( new-style default path is $XDG_CONFIG_HOME/easybuild/config.cfg)
  • the legacy fallback path <installpath>/easybuild/ ( only default/fallback path is $XDG_CONFIG_HOME/easybuild/config.cfg)

Likewise, the following legacy environment variables allowed to override selected configuration settings:

  • $EASYBUILDBUILDPATH: build path to be used by EasyBuild ( use $EASYBUILD_BUILDPATH instead )
  • $EASYBUILDINSTALLPATH: install path to be used by EasyBuild ( use $EASYBUILD_INSTALLPATH instead )
  • $EASYBUILDSOURCEPATH: source path to be used by EasyBuild ( use $EASYBUILD_SOURCEPATH instead )
  • $EASYBUILDPREFIX: build/install/source path prefix to be used ( use $EASYBUILD_PREFIX instead )

We strongly advise to switch to the new way of configuring EasyBuild as soon as possible, since the legacy configuration style will no longer be supported in EasyBuild v2.x.

How EasyBuild used to be configured in the early days

Configuring EasyBuild is done by providing a configuration file.

EasyBuild expects the configuration file to contain valid Python code, because it executes its contents (using exec). The rationale is that this approach provides a lot of flexibility for configuring EasyBuild.

EasyBuild will use the file that is provided by the path/filename in the following order of preference:

  • path/filename specified on the EasyBuild command line (using --config),
  • path/filename obtained from the environment variable EASYBUILDCONFIG (if it is defined)
  • $HOME/.easybuild/ (as of EasyBuild v1.1)
  • the (default) configuration file at <path where EasyBuild was installed>/easybuild/

Configuration variables

The configuration file must define the following five variables: build_path, install_path, source_path, repository, and log_format. If one of them is not defined, EasyBuild will complain and exit.

Build path (required)

The build_path variable specifies the directory in which EasyBuild builds its software packages.

Each software package is (by default) built in a subdirectory of the build_path under <name>/<version>/<toolchain><versionsuffix>.

Note that the build directories are emptied by EasyBuild when the installation is completed (by default).

Install path (required)

The install_path variable specifies the directory in which EasyBuild installs software packages and the corresponding module files.

The packages themselves are installed under install_path/software in their own subdirectory aptly named <name>/<version>-<toolchain><versionsuffix> (by default), where name is the package name. The corresponding module files are installed under install_path/modules.


After the configuration, you need to make sure that $MODULEPATH environment variable is extended with the modules/all subdirectory of the install_path, i.e.:

export MODULEPATH=<install_path>/modules/all:$MODULEPATH

It is probably a good idea to add this to your (favourite) shell .rc file, e.g., .bashrc, and/or the .profile login scripts, so you do not need to adjust the $MODULEPATH variable every time you start a new session.

Source path (required)

The source_path variable specifies the directory in which EasyBuild looks for software source and install files.

Similarly to the configuration file lookup, EasyBuild looks for the installation files as given by the sources variable in the .eb easyconfig file, in the following order of preference:

  • <source_path>/<name>: a subdirectory determined by the name of the software package
  • <source_path>/<letter>/<name>: in the style of the easyblocks/easyconfigs directories: in a subdirectory determined by the first letter (in lower case) of the software package and by its full name
  • <source_path>: directly in the source path

Note that these locations are also used when EasyBuild looks for patch files in addition to the various easybuild/easyconfigs directories that are listed in the $PYTHONPATH.