$ git clone -n https://src.fedoraproject.org/rpms/rubygem-gtksourceview3.git /var/lib/mock/f41-build-768799-13481/root/chroot_tmpdir/scmroot/rubygem-gtksourceview3
Cloning into '/var/lib/mock/f41-build-768799-13481/root/chroot_tmpdir/scmroot/rubygem-gtksourceview3'...
$ git fetch origin dbab5c0a76f5a416187b321b43f5d2f9f50aa2c4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-gtksourceview3
 * [new ref]         dbab5c0a76f5a416187b321b43f5d2f9f50aa2c4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dbab5c0 4.2.2 entry