Nomenclature and concepts

Deb

Deb files have a "control" file with a set of fields that contain the dependency data:

• Depends - States a required dependency on another plugin with optional version specification
• Recommends - State recommended depenendecy
• Suggests - States a suggested dependency
• Pre-Depends - States a dependency that has to be configure before installation
• Build-Depends - Not relevant
• Build-Depends-Indep - Not relevant

Each field list a set of packages separated with comma (","). Where a dependency is either one of more packages, each option is separated with a bar ("|").

Depends: libc6 (>= 2.2.1), exim | mail-transport-agent

Virtual packages

In addition Deb support a "virtual package" concept where more than one package can "implement" a package name. This give the user an option to choose an implementation when a package installed.

For example, both "openjdk", "sun-jdk" and "gcj" may packages may Provide "java".

Replacement

Deb also has a "Replaces" flag with two purposes:

• "this package replace files in package foo"
• "this package replaces this package entirely"

References

• http://www.debian.org/doc/debian-policy/ch-relationships.html

Rpm

Reference: http://rpm5.org/docs/rpm-guide.html#ch-dependencies

• Requires, which tracks the capabilities a package requires
• Provides, which tracks the capabilities a package provides for other packages
• Conflicts, which describes the capabilities that if installed, conflict with capabilities in a package
• Obsoletes, which describes the capabilities that this package will make obsolete

Possible mappings

provides defines a virtual package which is provided by the package being built
requires identifies a package that is required to be installed for the package being built to operate correctly
conflicts