$ git clone -n https://src.fedoraproject.org/rpms/rust-hashbrown0.12.git /var/lib/mock/f38-build-side-43-rust-devel-1404489-31202/root/chroot_tmpdir/scmroot/rust-hashbrown0.12
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1404489-31202/root/chroot_tmpdir/scmroot/rust-hashbrown0.12'...
$ git fetch origin e6c8d87b3ae57e3583fb93a456c8a156822ac6ba:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-hashbrown0.12
 * [new ref]         e6c8d87b3ae57e3583fb93a456c8a156822ac6ba -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e6c8d87 Initial Fedora package