$ git clone -n https://src.fedoraproject.org/rpms/rust-glib0.19.git /var/lib/mock/f42-build-side-1-3504291-45983/root/chroot_tmpdir/scmroot/rust-glib0.19
Cloning into '/var/lib/mock/f42-build-side-1-3504291-45983/root/chroot_tmpdir/scmroot/rust-glib0.19'...
$ git fetch origin 517132308b3e84118601f0af39c2acb0c83c7527:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-glib0.19
 * [new ref]         517132308b3e84118601f0af39c2acb0c83c7527 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5171323 compat package no longer needed