Comment # 19 on bug 1212835 from Jan Engelhardt

>Also please describe your vision how usrmerge is going to be supported in kmod.

Well certainly not by breaking the API. The linux kernel itself is known to, in
general, revert patches that break public APIs.

The other angle in package maintenance is that every patch adds to the
complexity multiplied by the time they have to be lugged around. {at, bash,
rpm} are prime examples of such sad stories, and for some patches, you also
have to answer to users why the program does not behave the same as upstream.