Julien Lepiller (2019-05-10 08:23:22 +0200) wrote: > >[…] What I don't get is *why* having two different versions of > >``python-attrs`` in the profile is considered an error. My understanding > >was that two different packages in the profile should be able to depend on > >different versions of the same library without problems, since they are > >referred by its absolute path in the store so they don't conflict. I > >understand that I may not directly ``guix install`` two versions of the > >same package (because the may e.g. put the same entry under > >``$GUIX_PROFILE/bin``), but in my case ``python-attrs`` is just a > >dependency package which doesn't show up in ``guix package -I``. > > > >Can anybody shed some light on the issue? Thanks! […] > > Hi, > > With packages written in C for instance you're right: dependencies are > directly embeded into binaries. With python however, we cannot embed store > paths by default, so we use propagated-inputs instad of regular > inputs. Propagated inputs are installed in the profile along with their > dependant, recursively, hence the conflict. > > With executable packages, we could try and wrap packages to define a > PYTHONPATH, so we don't have to use propagated inputs, but that's not > possible with libraries.
Aaah ok, it's clear now. Since you mentioned them, I looked for ``propagated-inputs`` in the fine Guix manual and got the extra details from sections "Invoking ‘guix package’" (regarding the ``--install`` option) and "‘package’ Reference" (regarding ``propagated-inputs``). Thank you very much! -- Ivan Vilata i Balaguer -- https://elvil.net/
