$ git clone -n https://src.fedoraproject.org/rpms/rust-socketpair.git /var/lib/mock/f42-build-side-1-3498112-45961/root/chroot_tmpdir/scmroot/rust-socketpair
Cloning into '/var/lib/mock/f42-build-side-1-3498112-45961/root/chroot_tmpdir/scmroot/rust-socketpair'...
$ git fetch origin 6ea2a206ed7f8cb0538fcc3cdab6a44872fe2bd5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-socketpair
 * [new ref]         6ea2a206ed7f8cb0538fcc3cdab6a44872fe2bd5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6ea2a20 Update to 0.19.6; Fixes: RHBZ#2350522