PackagingDrafts/ExplicitRequires

Addition to ReviewGuidelines

MUST: A package's list of dependencies must not contain any unnecessary explicit Requires on libraries.

Addition to Packaging Guidelines

Explicit Requires

Packages must not contain explicit Requires on libraries except when absolutely necessary. When explicit library Requires are necessary, there should be a spec file comment justifying it.

We generally rely on rpmbuild to automatically add dependencies on library SONAMEs. Modern package management tools are capable of resolving such dependencies to determine the required packages. Explicit dependencies on specific package names may aid the inexperienced user, who attempts at installing RPM packages manually, however, history has shown that such dependencies add confusion when library/files are moved from one package to another, when packages get renamed, when one out of multiple alternative packages would suffice, and when versioned explicit dependencies become out-of-date and inaccurate. Additionally, in some cases, old explicit dependencies on package names require unnecessary updates/rebuilds. For example, Fedora packages are only required to retain historical provides for two full release cycles.

Exemplary rationale for a versioned explicit dependency:

  # The automatic dependency on libfubar.so.1 is insufficient,
  # as we strictly need at least the release that fixes two segfaults.
  Requires: libfubar >= 0:1.2.3-7

Packagers should revisit an explicit dependency as appropriate to avoid it becoming inaccurate and superfluous. For instance in the example above, when no current Fedora release shipped with libfubar < 1.2.3-7, it is no longer necessary to list the explicit, versioned requirement.