$ git clone -n https://src.fedoraproject.org/rpms/rust-copypasta.git /var/lib/mock/f40-build-2717987-72846/root/chroot_tmpdir/scmroot/rust-copypasta
Cloning into '/var/lib/mock/f40-build-2717987-72846/root/chroot_tmpdir/scmroot/rust-copypasta'...
$ git fetch origin 7939808ee099db6231caff5fc97697dfeb5bdaa9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-copypasta
 * [new ref]         7939808ee099db6231caff5fc97697dfeb5bdaa9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7939808 Update to 0.10.1 (rhbz#2262787)