$ git clone -n https://src.fedoraproject.org/rpms/rust-proc-mounts0.2.git /var/lib/mock/f41-build-1254082-23018/root/chroot_tmpdir/scmroot/rust-proc-mounts0.2
Cloning into '/var/lib/mock/f41-build-1254082-23018/root/chroot_tmpdir/scmroot/rust-proc-mounts0.2'...
$ git fetch origin 15b3e1084be958fefba57fe754b71e58ec4be76d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-proc-mounts0.2
 * [new ref]         15b3e1084be958fefba57fe754b71e58ec4be76d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 15b3e10 compat package no longer needed