$ git clone -n https://src.fedoraproject.org/rpms/harfbuzz.git /var/lib/mock/f41-build-side-1-3084768-39067/root/chroot_tmpdir/scmroot/harfbuzz
Cloning into '/var/lib/mock/f41-build-side-1-3084768-39067/root/chroot_tmpdir/scmroot/harfbuzz'...
$ git fetch origin 77b020405faa68d7c376c4f8016f610fd0ade39f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/harfbuzz
 * [new ref]         77b020405faa68d7c376c4f8016f610fd0ade39f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 77b0204 Split harfbuzz-cairo as a separate subpackage from harfbuzz-devel