$ git clone -n https://src.fedoraproject.org/rpms/rust-libsodium-sys.git /var/lib/mock/f40-build-2082690-49856/root/chroot_tmpdir/scmroot/rust-libsodium-sys
Cloning into '/var/lib/mock/f40-build-2082690-49856/root/chroot_tmpdir/scmroot/rust-libsodium-sys'...
$ git fetch origin ac898b3e096832b2a96d18c9bf32453bbd1ed88d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-libsodium-sys
 * [new ref]         ac898b3e096832b2a96d18c9bf32453bbd1ed88d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ac898b3 Unconditionally use pkg-config to link against system libsodium