Re: automake-1.17 fails with latest Perl (5.41.8) - Possible precedence problem between ! and numeric eq (==)

[Jacob Bachmeyer]

On 2/4/25 17:56, Karl Berry wrote:
>      If the concern is making certain that new Perl warnings are noticed,
>      simply putting PERL5OPT='-Mwarnings=FATAL,all' in the environment when
>      running the testsuite should accomplish that.
>
> Thanks for the suggestion. I put a note into HACKING about it.
>
> I also tried running the tests that way, and discovered one intentional
> warning in t/parallel-tests-log-compiler-example.sh (and so the test
> failed). I added an explicit "use warnings" there to override the envvar
> setting. -k

If a plain "use warnings;" in a script overrides setting 
PERL5OPT=-Mwarnings=FATAL,all in the environment, then I was wrong and 
using PERL5OPT like that will /not/ make warnings in Automake code 
fatal, since every Automake module (should) "use warnings;" and thus end 
up overriding them to the default of being non-fatal.  Oops.

TIMTOWTDI:

Automake would need to choose an environment variable or other means of 
selecting fatal warnings mode and do something like:

   use if defined $ENV{'AUTOMAKE_FATAL_PERL_WARNINGS'},
        warnings => FATAL => 'all';

... in each file to select fatal warnings if desired.  It seems that the 
above must appear *after* the basic "use warnings;" line.  The "if" 
pragma was introduced in Perl 5.6.2 according to corelist(1).

Note that the test above, for concision, checks only that 
AUTOMAKE_FATAL_PERL_WARNINGS *exists* in the environment and ignores its 
value.


-- Jacob