diff options
| -rw-r--r-- | lib/spack/docs/packaging_guide.rst | 28 | ||||
| -rw-r--r-- | lib/spack/spack/concretize.py | 24 |
2 files changed, 47 insertions, 5 deletions
diff --git a/lib/spack/docs/packaging_guide.rst b/lib/spack/docs/packaging_guide.rst index 15c3e0ca7f..a4982a9071 100644 --- a/lib/spack/docs/packaging_guide.rst +++ b/lib/spack/docs/packaging_guide.rst @@ -431,7 +431,7 @@ how to compare and sort numeric versions. Some Spack versions involve slight extensions of numeric syntax; for example, ``py-sphinx-rtd-theme@0.1.10a0``. In this case, numbers are always considered to be "newer" than letters. This is for consistency -with `RPM <https://bugzilla.redhat.com/show_bug.cgi?id=50977>`. +with `RPM <https://bugzilla.redhat.com/show_bug.cgi?id=50977>`_. Spack versions may also be arbitrary non-numeric strings; any string here will suffice; for example, ``@develop``, ``@master``, ``@local``. @@ -458,6 +458,32 @@ The logic behind this sort order is two-fold: ``develop`` version to satisfy dependencies like ``depends_on(abc, when="@x.y.z:")`` +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Concretization Version Selection +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +When concretizing, many versions might match a user-supplied spec. +For example, the spec ``python`` matches all available versions of the +package ``python``. Similarly, ``python@3:`` matches all versions of +Python3. Given a set of versions that match a spec, Spack +concretization uses the following priorities to decide which one to +use: + +#. If the user provided a list of versions in ``packages.yaml``, the + first matching version in that list will be used. + +#. If one or more versions is specified as ``preferred=True``, in + either ``packages.yaml`` or ``package.py``, the largest matching + version will be used. ("Latest" is defined by the sort order + above). + +#. If no preferences in particular are specified in the package or in + ``packages.yaml``, then the largest matching non-develop version + will be used. By avoiding ``@develop``, this prevents users from + accidentally installing a ``@develop`` version. + +#. If all else fails and ``@develop`` is the only matching version, it + will be used. ^^^^^^^^^^^^^ Date Versions diff --git a/lib/spack/spack/concretize.py b/lib/spack/spack/concretize.py index cf8cf2965c..9c9e9e10ff 100644 --- a/lib/spack/spack/concretize.py +++ b/lib/spack/spack/concretize.py @@ -180,16 +180,32 @@ class DefaultConcretizer(object): v for v in pkg.versions if any(v.satisfies(sv) for sv in spec.versions)] + # The keys below show the order of precedence of factors used + # to select a version when concretizing. The item with + # the "largest" key will be selected. + # + # NOTE: When COMPARING VERSIONS, the '@develop' version is always + # larger than other versions. BUT when CONCRETIZING, + # the largest NON-develop version is selected by + # default. keys = [( + # ------- Special direction from the user # Respect order listed in packages.yaml yaml_index.get(v, -1), + # The preferred=True flag (packages or packages.yaml or both?) pkg.versions.get(Version(v)).get('preferred', False), - # @develop special case - v.isdevelop(), - # Numeric versions more preferred than non-numeric - v.isnumeric(), + + # ------- Regular case: use latest non-develop version by default. + # Avoid @develop version, which would otherwise be the "largest" + # in straight version comparisons + not v.isdevelop(), + # Compare the version itself + # This includes the logic: + # a) develop > everything (disabled by "not v.isdevelop() above) + # b) numeric > non-numeric + # c) Numeric or string comparison v) for v in unsorted_versions] keys.sort(reverse=True) |