> The old serial testsuite driver is still supported, and can be activated
> by the 'serial-tests' option (introduced by commit 'v1.11-1989-gdeb7773'
> of 2012-02-20, "automake: new option 'serial-tests'").
> * lib/Automake/Options.pm: Now, the 'parallel-tests' option is a no-op
> (but still explicitly recognized, for backward compatibility), while the
> 'serial-tests' option is recognized and registered.
> * automake.in: Adjust to ensure that the parallel test harness is used by
> default; mostly, this amounts at using "! option('serial-tests')" where
> "option('parallel-tests')" was used before.
> * NEWS, doc/automake.texi: Update.
> * configure.ac (AM_INIT_AUTOMAKE): Drop 'parallel-tests' option, is
> redundant now.
> * defs: In the generated AM_INIT_AUTOMAKE call, use the 'serial-tests'
> when the serial testsuite harness is to be used, and no option otherwise.
> * lib/am/check.am: Use (static) conditional '%SERIAL_TESTS%' instead of
> conditional '%PARALLEL_TESTS%'.
> * lib/test-driver: Adjust heading comments.
> * t/ax/extract-testsuite-summary.pl: Likewise.
> * t/check-exported-srcdir.sh: Likewise.
> * t/check-subst.sh: Likewise.
> * t/java-compile-run-nested.sh: Likewise.
> * t/parallel-tests-dry-run-1.sh: Likewise.
> * t/parallel-tests-dry-run-2.sh: Likewise.
> * t/parallel-tests-interrupt.sh: Likewise.
> * t/parallel-tests-many.sh: Likewise.
> * t/test-metadata-global-log.sh: Likewise.
> * t/tests-environment-backcompat.sh: Likewise.
> * m4/init.m4 (AM_INIT_AUTOMAKE): Adjust a comment.
> * t/check8.sh: Likewise.
> * t/check-tests-in-builddir.sh: Likewise.
> * t/java-compile-run-flat.sh: Adjust a botched comment.
> * t/ax/tap-summary-aux.sh: Remove explicit use of the 'parallel-tests'
> * t/ax/testsuite-summary-checks.sh: Likewise.
> * t/aclocal-path-precedence.sh: Likewise.
> * t/dist-aux-many-subdirs.sh: Likewise.
> * t/parallel-tests-no-color-in-log.sh: Likewise.
> * t/parallel-tests-reset-term.sh: Likewise.
> * t/parallel-tests-subdir.sh: Likewise.
> * t/check-no-test-driver.sh: Fix setup to adjust to the changed
> semantics. Update heading comments.
> * t/parallel-tests-driver-install.sh: Adjust to the new semantic.
> * t/test-driver-is-distributed.sh: Simplified according to the
> new semantics.
> Signed-off-by: Stefano Lattarini <stefano.lattarini@...>
> I will push (to master) this by tomorrow if there is no review by then.