I was preparing to install hplip-3.20.6 in order to test hplip-plugin-3.20.6, but unfortunately we don't presently have the patch(es) needed to build any of the 3.20.x versions of hplip for musl libc in ::gentoo yet (nor ::musl FTR).
As agreed with @billie, happy to submit the required patches for him to include, as they shouldn't affect [normal] glibc installations.
Alpine linux has a full set of patches for 3.20.5 at https://git.alpinelinux.org/aports/tree/testing/hplip but these need sync'ing with our own, which I'm happy to do & test.
Assigning to self, as need to log some Z's presently, but making notes to revisit asap. @Chewi will know I've promised him a PR for hplip-plugin once tested :P
Will update as I make progress.
No problem with including musl patches. Two things however:
First please make sure that upstream is aware of these patches. At a quick glance I found nothing there.
Second you may look also at the OpenWrt Project  and The Void Linux distribution  which also support musl and hplip.
Btw. hplip is at 3.20.6 now.
Usually I do check in with void too, as it can be a slow process for musl distros to keep track of upstream releases!
I'll do my best to push necessary patches upstream, I do believe they are receptive to changes and PR, although I'm not 100% at present what their preferred method is.
Thanks for doing the 3.20.6 bump .. for some reason I've lost the email notification I had about the update! I see you've also picked up a dbus issue in another bug too!
I found an upstream bug for musl support with three patches: https://bugs.launchpad.net/hplip/+bug/1886527
(In reply to tt_1 from comment #3)
> I found an upstream bug for musl support with three patches:
Thanks for this, just what we need. Hopefully if these are accepted we can stop carrying downstream patches.
I'm overdue testing the new releases on my musl boxes, but will endeavour to PR these over the next week or so.
how is the situation with the hplip-plugins package? Does it tolerate a musl libc.so?
(In reply to tt_1 from comment #5)
> how is the situation with the hplip-plugins package? Does it tolerate a musl
I haven't tried but I think it does, with the exception of bb_orblite.so.
well, and it seems that hplip-plugins just got a useflag to filter these out, happy days! :)