automake: Serial Test Harness

1 
1 15.2.2 Older (and discouraged) serial test harness
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1 
1 First, note that today the use of this harness is strongly discouraged
1 in favour of the parallel test harness (⇒Parallel Test Harness).
1 Still, there are _few_ situations when the advantages offered by the
1 parallel harness are irrelevant, and when test concurrency can even
1 cause tricky problems.  In those cases, it might make sense to still use
1 the serial harness, for simplicity and reliability (we still suggest
1 trying to give the parallel harness a shot though).
1 
1    The serial test harness is enabled by the Automake option
1 ‘serial-tests’.  It operates by simply running the tests serially, one
1 at the time, without any I/O redirection.  It’s up to the user to
1 implement logging of tests’ output, if that’s required or desired.
1 
1    For historical and implementation reasons, the ‘AM_TESTS_ENVIRONMENT’
1 variable is _not_ supported by this harness (it will be silently ignored
1 if defined); only ‘TESTS_ENVIRONMENT’ is, and it is to be considered a
1 developer-reserved variable.  This is done so that, when using the
1 serial harness, ‘TESTS_ENVIRONMENT’ can be defined to an invocation of
1 an interpreter through which the tests are to be run.  For instance, the
1 following setup may be used to run tests with Perl:
1 
1      TESTS_ENVIRONMENT = $(PERL) -Mstrict -w
1      TESTS = foo.pl bar.pl baz.pl
1 
1 It’s important to note that the use of ‘TESTS_ENVIRONMENT’ endorsed here
1 would be _invalid_ with the parallel harness.  That harness provides a
1 more elegant way to achieve the same effect, with the further benefit of
11 freeing the ‘TESTS_ENVIRONMENT’ variable for the user (⇒Parallel
 Test Harness).
1 
1    Another, less serious limit of the serial harness is that it doesn’t
1 really distinguish between simple failures and hard errors; this is due
1 to historical reasons only, and might be fixed in future Automake
1 versions.
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