$ git clone -n https://src.fedoraproject.org/rpms/rust-below-config.git /var/lib/mock/f42-build-side-1-3499886-45966/root/chroot_tmpdir/scmroot/rust-below-config
Cloning into '/var/lib/mock/f42-build-side-1-3499886-45966/root/chroot_tmpdir/scmroot/rust-below-config'...
$ git fetch origin f1dd93c3af2e6954f5b88de6363d24cb63f9292c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-below-config
 * [new ref]         f1dd93c3af2e6954f5b88de6363d24cb63f9292c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f1dd93c Update to 0.9.0; Fixes: RHBZ#2347619