$ git clone -n https://src.fedoraproject.org/rpms/rust-cairo-sys-rs0.19.git /var/lib/mock/f42-build-side-1-3540449-46574/root/chroot_tmpdir/scmroot/rust-cairo-sys-rs0.19
Cloning into '/var/lib/mock/f42-build-side-1-3540449-46574/root/chroot_tmpdir/scmroot/rust-cairo-sys-rs0.19'...
$ git fetch origin bdcf0d8bf95c68356aaf3e4bd5f311e91c4dd1a3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cairo-sys-rs0.19
 * [new ref]         bdcf0d8bf95c68356aaf3e4bd5f311e91c4dd1a3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bdcf0d8 compat package no longer needed