$ git clone -n https://src.fedoraproject.org/rpms/rust-crossbeam-epoch.git /var/lib/mock/f39-build-1521578-35848/root/chroot_tmpdir/scmroot/rust-crossbeam-epoch
Cloning into '/var/lib/mock/f39-build-1521578-35848/root/chroot_tmpdir/scmroot/rust-crossbeam-epoch'...
$ git fetch origin 994e12ee81d3d9f4a9c88431b91c3c3e8a3620aa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-crossbeam-epoch
 * [new ref]         994e12ee81d3d9f4a9c88431b91c3c3e8a3620aa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 994e12e Remove redundant clone() call to fix builds with Rust 1.73+