The rationale behind maemo-release

The maemo-release package seeks to address the situation wherein a source package is forked into gregale/bora/chinook/diablo/fremantle versions of itself because one set of Build-Depends does not work for all distributions.

Example: Fremantle provides libgstfarsight0.10-dev, whereas previous distributions do not. pidgin needs to Build-Depend on it for voice/video support to be compiled in during the build process. However, the libgstfarsight0.10-dev package does not exist in any previous distribution.

This results in having to provide a different debian/control file for the various distributions, which in turn forces one to make a different debian/changelog file for the various distributions. At this point, different distributions have different source packages.

To prevent this one reason for forking the source package, we need the maemo-release package. Then, knowing which distribution(s) contain a needed package foo, we can create an appropriate debian/control entry.

Example: Suppose Bora and Diablo contain package foo, but the other distributions do not. The corresponding debian/control Build-Depends entry will be:

Build-Depends: package1-dev, 
 foo | maemo-version (= 1.0.0) | maemo-version (= 3.0.0) | maemo-version (= 5.0.0),

This way you can describe intervals of distributions wherein a certain package has become available. Examples:

  (1.0.0) Gregale     (2.0.0) Bora     (3.0.0) Chinook     (4.0.0) Diablo     (5.0.0) Fremantle  
Example: foo | maemo-release (< 3.0.0)
foo is absent foo is present
Example: foo | maemo-release (< 2.0.0) | maemo-release (> 4.0.0)
foo is absent foo is present foo is absent