$ git clone -n https://src.fedoraproject.org/rpms/R-MatrixGenerics.git /var/lib/mock/f37-build-side-32-misc-devel-355784-15585/root/chroot_tmpdir/scmroot/R-MatrixGenerics
Cloning into '/var/lib/mock/f37-build-side-32-misc-devel-355784-15585/root/chroot_tmpdir/scmroot/R-MatrixGenerics'...
$ git reset --hard d9842cc171b5d666fb67d71a76433516acf4f3ce
HEAD is now at d9842cc update to 1.8.1, rebuild for R 4.2.1