$ git clone -n https://src.fedoraproject.org/rpms/rust-gdk-sys0.15.git /var/lib/mock/f41-build-1269628-23100/root/chroot_tmpdir/scmroot/rust-gdk-sys0.15
Cloning into '/var/lib/mock/f41-build-1269628-23100/root/chroot_tmpdir/scmroot/rust-gdk-sys0.15'...
$ git fetch origin 0f30c4f4a163fe24dae074d987bbe7b227d6b446:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gdk-sys0.15
 * [new ref]         0f30c4f4a163fe24dae074d987bbe7b227d6b446 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0f30c4f compat package no longer needed