$ git clone -n https://src.fedoraproject.org/rpms/rubygem-sass.git /var/lib/mock/f41-build-1093598-19988/root/chroot_tmpdir/scmroot/rubygem-sass
Cloning into '/var/lib/mock/f41-build-1093598-19988/root/chroot_tmpdir/scmroot/rubygem-sass'...
$ git fetch origin 2e59ca9e2cdd0e9c8420f906d1c8b95a2cc86a74:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-sass
 * [new ref]         2e59ca9e2cdd0e9c8420f906d1c8b95a2cc86a74 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2e59ca9 Eliminate use of obsolete %patchN syntax (#2283636)