Don't make parallel tests by default.
Don't make parallel tests by default.

It very much seem that ctest cannot reliably run parallel tests. I see no
reason why innocuous tests such as test_strlcat could fail if we're doing
parallel tests, and pass otherwise.

For re-enabling parallel tests, run the coverage script with
EXTRA_MAKETEST_ARGS=ARGS=-j2 (for instance. -j8 works much better to
trigger test failures).

mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs