Re: One failed self test on Alpine Linux

[Akim Demaille]

Hi Jeffrey,

Sorry for the slow motion on this issue, but it is quite
delicate to try to understand what is going on with such
huge logs.

> Le 16 janv. 2021 à 22:10, Jeffrey Walton <noloader@gmail.com> a écrit :
> 
> On Sat, Jan 16, 2021 at 9:33 AM Akim Demaille <akim@lrde.epita.fr> wrote:
>> 
>> ...
>> So please, let's try again.  I have again prepared another tarball.
>> 
>> https://www.lrde.epita.fr/~akim/private/bison/bison-3.7.4.273-d85e.tar.gz
>> https://www.lrde.epita.fr/~akim/private/bison/bison-3.7.4.273-d85e.tar.lz
>> https://www.lrde.epita.fr/~akim/private/bison/bison-3.7.4.273-d85e.tar.xz
>> 
>> make check-local TESTSUITEFLAGS='271 -d'
>> TIME_LIMIT=1 ./src/bison -Tcex -Wcex ./tests/testsuite.dir/271/input.y 
>> >/tmp/271.log 2>&1
> 
> The 271 test on Alpine 3.10:
>  * https://www.cryptopp.com/271-3.log.zip
> 
> The 271 test on Alpine 3.12:
>  * https://www.cryptopp.com/271-4.log.zip
> 
> Maybe you can diff them to quickly determine the difference.

To summarize, you said the test passes in 3.12 but fails in 3.10.
The failure is as follows:

>> input.y: warning: reduce/reduce conflict on token $end [-Wcounterexamples]
>> -  Example: b d .
>> +  First example: b d . $end
>>  First reduce derivation
>> -    a
>> -    `-> b d .
>> +    $accept
>> +    `-> a         $end
>> +        `-> b d .
>> +  Second example: b d . $end
>>  Second reduce derivation
>> -    a
>> -    `-> b d
>> -          `-> d .
>> +    $accept
>> +    `-> a             $end
>> +        `-> b d
>> +              `-> d .

i.e., we have "First example: b d . $end" in the output, although we
expected "Example: b d .".  But in the two logs you sent we appear
to have what is actually expected.

$ grep -E '(First example|Example): b' /tmp/3.10.short.log
    4 c:  First example: b • c A A $end
  First example: b c • A
  First example: b c • c A A $end
  First example: b c • A
  Example: b d •
$ grep -E '(First example|Example): b' /tmp/3.12.short.log
    4 c:  First example: b • c A A $end
  First example: b c • A
  First example: b c • c A A $end
  First example: b c • A
  Example: b d •

This is very very weird.  Did the test pass?

Meanwhile we have released Bison 3.7.5 which includes a fix for
counterexamples.  I'm convinced the fix is completely unrelated
to your issue.  Could you however try yet again with the following
tarball, which includes the fix of 3.7.5?

https://www.lrde.epita.fr/~akim/private/bison/bison-3.7.5.299-6a6b.tar.gz
https://www.lrde.epita.fr/~akim/private/bison/bison-3.7.5.299-6a6b.tar.lz
https://www.lrde.epita.fr/~akim/private/bison/bison-3.7.5.299-6a6b.tar.xz

FTR, the procedure is:

make check-local TESTSUITEFLAGS='271 -d'
TIME_LIMIT=1 ./src/bison -Tcex -Wcex ./tests/testsuite.dir/271/input.y 
>/tmp/271.log 2>&1

Please, be sure to use exactly that version of bison on
both architectures.  Cheers!