$ git clone -n https://src.fedoraproject.org/rpms/rubygem-sassc.git /var/lib/mock/f39-build-1504110-35008/root/chroot_tmpdir/scmroot/rubygem-sassc
Cloning into '/var/lib/mock/f39-build-1504110-35008/root/chroot_tmpdir/scmroot/rubygem-sassc'...
$ git fetch origin 6174ecc2a0e13186b2619c7328220cac9264b634:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-sassc
 * [new ref]         6174ecc2a0e13186b2619c7328220cac9264b634 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6174ecc Fix tests to work with rubygem-minitest-5.19.0