$ git clone -n https://src.fedoraproject.org/rpms/rust-test-case.git /var/lib/mock/f40-build-2093792-50336/root/chroot_tmpdir/scmroot/rust-test-case
Cloning into '/var/lib/mock/f40-build-2093792-50336/root/chroot_tmpdir/scmroot/rust-test-case'...
$ git fetch origin 8a3607452c9c3307a89cf30e1bdc7d5a2d405aeb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-test-case
 * [new ref]         8a3607452c9c3307a89cf30e1bdc7d5a2d405aeb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a36074 Update to version 3.2.1; Fixes RHBZ#2057213