The libffi problem narrows things down to two possible solutions. I don't know which would be easier for releng.

A - Tag the rawhide build of ghc and ghc-rpm-macros into an epel9 side-tag. Specifically ghc-8.10.5-116.fc36 and ghc-rpm-macros-2.3.11-1.fc36.

B - Somehow import the latest CentOS Stream 9 build (ghc-8.8.4-113.el9), and the libffi-3.4.2-4.el9 into an epel9 side-tag. libffi-3.4.2-4.el9 was the transition libffi, and contains the sub-package compat-libffi3.1-3.4.2-4.el9.

Looking at things, I think (A) would be easiest because those builds are already in koji, so it's just a matter of doing the tags. But that is just my opinion.

libffi is at 3.4 in rawhide now if that helps - ghc-8.10.5-116.fc36 is built against it.

Yes I just tested this myself - ghc-8.10.5-116.fc36 works so let's go with that, please

Thanks Troy and Miro!

I just opened https://bugzilla.redhat.com/show_bug.cgi?id=2040623
to request having llvm11 for epel9 since that is a pre-requisite for aarch64.

Okay I will update here once have I built llvm11 for epel9

I just pushed llvm11 to bodhi for epel9 (it took some time due to build issues).
So it ought to be possible to build with ghc now.

Could you please tag ghc-8.10.5-116.fc36 into an epel9 sidetag so that I can bootstrap ghc now?

@petersen to which side tag?

Okay, can you tag it into epel9-build-side-51211, thanks!

Done

$ koji list-tagged epel9-build-side-51211
Build                                     Tag                   Built by
----------------------------------------  --------------------  ----------------
ghc-8.10.5-116.fc36                       epel9-build-side-51211  churchyard

Thanks for your patience - I have finished bootstrapping ghc for epel9 and pushed it to Bodhi now.

Can I just close the sidetag? Or should the rawhide ghc be untagged first?
Maybe it doesn't matter to leave the tag on?

It should untag when you remove the side tag. ;) So, just remove the sidetag and we should be able to close this I think?

Thanks!