Hi,

ludo@gnu.org (Ludovic Courtès) writes:

> Andreas Enge <andreas@enge.fr> skribis:
>
>> I think we need a more sophisticated mechanism for separating package names
>> and versions, such as this:
>> - Try the compete string as a package name.
>> - If it does not exist, treat the part after the last dash as a version and
>>   the part before the last dash as the name.
>
> Attached is the beginning of a patch to do that.
>
> However, there are users of ‘package-specification->name+version+output’
> that still need to be adjusted, such as Emacs (in guix-main.scm.)  Also,
> the responsibility of trying NAME-VERSION is on each caller, which is
> not really satisfying.
>
> I’ll ponder it some more.  Suggestions welcome.

I had the same issue when trying to create a package named
'rxvt-unicode-256-color'.  I have tried to fix
‘package-name->name+version’ by matching the last hyphen and check if
the next character is a number.