$ git clone -n https://src.fedoraproject.org/rpms/rust-os_pipe.git /var/lib/mock/f45-build-43595-804/root/chroot_tmpdir/scmroot/rust-os_pipe
Cloning into '/var/lib/mock/f45-build-43595-804/root/chroot_tmpdir/scmroot/rust-os_pipe'...
$ git fetch origin 456b6d9d19dea903f21c4faa2d9a6807ec847956:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-os_pipe
 * [new ref]         456b6d9d19dea903f21c4faa2d9a6807ec847956 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 456b6d9 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild