Trying to build gnome-code-assistance results in the following error during source extraction:

$ makepkg --nobuild --nodeps --noprepare --skippgpcheck --skipinteg
==> Making package: gnome-code-assistance 3.16.1+15+gb9ffc4d-1 (Fri 04 Oct 2019 01:00:10 PM EDT)
==> WARNING: Skipping dependency checks.
==> Retrieving sources...
-> Cloning gnome-code-assistance git repo...
Cloning into bare repository '/home/eschwartz/git/archlinux/golang-rebuilds/sourcedest/gnome-code-assistance'...
remote: Enumerating objects: 3683, done.
remote: Counting objects: 100% (3683/3683), done.
remote: Compressing objects: 100% (1473/1473), done.
remote: Total 3683 (delta 2052), reused 3668 (delta 2044)
Receiving objects: 100% (3683/3683), 1.62 MiB | 2.01 MiB/s, done.
Resolving deltas: 100% (2052/2052), done.
==> WARNING: Skipping all source file integrity checks.
==> Extracting sources...
-> Creating working copy of gnome-code-assistance git repo...
Cloning into 'gnome-code-assistance'...
done.
fatal: reference is not a tree: b9ffc4dacaf2ff7f15dad7c2d7c68de6937ec038
==> ERROR: Failure while creating working copy of gnome-code-assistance git repo
Aborting...


In https://git.archlinux.org/svntogit/community.git/commit/trunk/PKGBUILD?h=packages/gnome-code-assistance&id=a7612ec217b85985368d303c31e9c45f9e409d9c the package was changed to build from git master to build from a commit that no longer exists and certainly doesn't seem to be on master; this is fragile and unreliable since the tree being referenced has no guarantee of existing and is pretty much guaranteed to stop existing due to periodic rebases. It is even called out as a "wip" branch.

-_commit=aad6437571461d35fe86c34a97f264e9bd7720c3 # master
+_commit=b9ffc4dacaf2ff7f15dad7c2d7c68de6937ec038 # wip/lantw/update-llvm-and-vala-versions

I'm not even sure what the change is supposed to do, since there is no commit message for this package update.

Can we stick to using only published revisions, and apply other non-published revisions as needed via e.g. patches?