diff options
| -rw-r--r-- | lib/spack/docs/packaging_guide.rst | 39 |
1 files changed, 25 insertions, 14 deletions
diff --git a/lib/spack/docs/packaging_guide.rst b/lib/spack/docs/packaging_guide.rst index 08d39a266a..6936b5e423 100644 --- a/lib/spack/docs/packaging_guide.rst +++ b/lib/spack/docs/packaging_guide.rst @@ -1345,20 +1345,31 @@ Additionally, dependencies may be specified for specific use cases: The dependency types are: - * **"build"**: made available during the project's build. The package will - be added to ``PATH``, the compiler include paths, and ``PYTHONPATH``. - Other projects which depend on this one will not have these modified - (building project X doesn't need project Y's build dependencies). - * **"link"**: the project is linked to by the project. The package will be - added to the current package's ``rpath``. - * **"run"**: the project is used by the project at runtime. The package will - be added to ``PATH`` and ``PYTHONPATH``. - -If not specified, ``type`` is assumed to be ``("build", "link")``. This is the -common case for compiled language usage. Also available are the aliases -``"alldeps"`` for all dependency types and ``"nolink"`` (``("build", "run")``) -for use by dependencies which are not expressed via a linker (e.g., Python or -Lua module loading). + * **"build"**: The dependency package is made available during the + package's build. While the package is built, the dependency + package's install directory will be added to ``PATH``, the + compiler include and library paths, as well as ``PYTHONPATH``. + This only applies during this package's build; other packages + which depend on this one will not know about the dependency + package. In other words, building another project Y doesn't know + about this project X's build dependencies. + * **"link"**: The dependency package is linked against by this + package, presumably via shared libraries. The dependency package + will be added to this package's run-time library search path + ``rpath``. + * **"run"**: The dependency package is used by this package at run + time. The dependency package will be added to both ``PATH`` and + ``PYTHONPATH`` at run time, but not during build time. **"link"** + and **"run"** are similar in that they both describe a dependency + that exists when the package is used, but they differ in the + mechanism: **"link"** is via shared libraries, and **"run"** via + an explicit search. + +If not specified, ``type`` is assumed to be ``("build", "link")``. +This is the common case for compiled language usage. Also available +are the aliases ``"alldeps"`` for all dependency types combined, and +``"nolink"`` (``("build", "run")``) for use by dependencies which are +not expressed via a linker (e.g., Python or Lua module loading). .. _setup-dependent-environment: |