$ git clone -n https://github.com/fedora-riscv/rust.git /var/lib/mock/f39-build-1667262-40809/root/chroot_tmpdir/scmroot/rust
Cloning into '/var/lib/mock/f39-build-1667262-40809/root/chroot_tmpdir/scmroot/rust'...
$ git fetch origin f4e244dfd795edd2791109c3ecc9926c1b8a3992:KOJI_FETCH_HEAD
From https://github.com/fedora-riscv/rust
 * [new ref]         f4e244dfd795edd2791109c3ecc9926c1b8a3992 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f4e244d Fix build on riscv64.