$ git clone -n https://src.fedoraproject.org/rpms/llvm12.git /var/lib/mock/f41-build-696638-12816/root/chroot_tmpdir/scmroot/llvm12
Cloning into '/var/lib/mock/f41-build-696638-12816/root/chroot_tmpdir/scmroot/llvm12'...
$ git fetch origin d592b977e772411329f97b9592f09f01429ed695:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/llvm12
 * [new ref]         d592b977e772411329f97b9592f09f01429ed695 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d592b97 Eliminate use of obsolete %patchN syntax (#2283636)