$ git clone -n https://src.fedoraproject.org/rpms/rubygem-gettext.git /var/lib/mock/f39-build-1499274-34744/root/chroot_tmpdir/scmroot/rubygem-gettext
Cloning into '/var/lib/mock/f39-build-1499274-34744/root/chroot_tmpdir/scmroot/rubygem-gettext'...
$ git fetch origin fc996eba553eaac58605a5c35ca1cac1af9b609b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-gettext
 * [new ref]         fc996eba553eaac58605a5c35ca1cac1af9b609b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fc996eb 3.4.9