$ git clone -n https://github.com/fedora-riscv/mvfst.git /var/lib/mock/f40-build-2692907-68276/root/chroot_tmpdir/scmroot/mvfst
Cloning into '/var/lib/mock/f40-build-2692907-68276/root/chroot_tmpdir/scmroot/mvfst'...
$ git fetch origin 70032cc087fd7ca7fa9dd7d63db9808788589569:KOJI_FETCH_HEAD
From https://github.com/fedora-riscv/mvfst
 * [new ref]         70032cc087fd7ca7fa9dd7d63db9808788589569 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 70032cc Add riscv64 support.