$ git clone -n https://src.fedoraproject.org/rpms/R-formatR.git /var/lib/mock/f40-build-1168905-21689/root/chroot_tmpdir/scmroot/R-formatR
Cloning into '/var/lib/mock/f40-build-1168905-21689/root/chroot_tmpdir/scmroot/R-formatR'...
$ git fetch origin 1550a7ad02e2300ec9fe15bf9f7508c187c3eb27:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-formatR
 * [new ref]         1550a7ad02e2300ec9fe15bf9f7508c187c3eb27 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1550a7a R-maint-sig mass rebuild