It is still under construction and content may change. Do not rely on the information on this page.
Rationale
rpm/yum treat a dependency (Requires) on “foo” as satisfiable by any available foo, regardless of architecture. The consequence of this is that on multilib systems, when the architecture of a dependency has not been specified (even though it is important), yum can install the wrong architecture build of the dependency—resulting in, most likely, a nonfunctional installation. This appears to happen when, for some reason, the correct architecture is not available to yum.
Making Requires Arch-Specific
Explicit requires must be made arch-specific by appending the macro %{?_isa} to the package name. For instance,
Requires: foo
becomes
Requires: foo%{?_isa}
When To Do It
If a dependency really can be satisfied by a build for any architecture, clearly there's no reason to make the dependency architecture-specific. But it does matter in these scenarios:
- A library in the dependency is
dlopen'd. - A non-noarch
-develpackage depends on another-develpackage. - A non-noarch subpackage's dependency on its main package.
So, unless you have a very good reason to not make an explicit dependency architecture specific (and if so, be sure to document it in the spec file with a comment), you MUST do it.