Re: make test

[John Mandereau]

Sorry for the delay Phil, I had missed this message.
Le mercredi 08 août 2012 à 09:59 +0100, Phil Holmes a écrit :
> I've been looking at how the regression test comparison works.  The first 
> thing I find is that we have 2 effectively duplicate, but different, pages 
> on running regtest comparisons:
> 
> http://lilypond.org/doc/v2.15/Documentation/contributor/verify-regression-tests
> http://lilypond.org/doc/v2.15/Documentation/contributor/regtest-comparison
> 
> I think the latter is probably more accurate.  I think it would be best to 
> delete one and point to the other?

+1


> I've also been benchmarking.  For example, I know that make CPU_COUNT=9 test 
> is _much_ faster than make test, but the make -j9 test isn't worth doing - 
> most of the time is spent building the single regtest document, which 
> lilypond parallelises much better than make.  I have had errors using -jX so 
> am slightly suspicious of that option.  I would like to add the best way to 
> parallelise the test process to the CG.

Which problems have you had with "make -jX test"?  They should be
identified and fixed: they are a probable symptom of missing
dependencies in the makefiles, that don't show up often because by
chance Make calls commands in a correct order.


> I've also been looking at how output-distance works.  Does anyone now 
> understand what this actually does?  From following the code, it looks to me 
> like it doesn't actually compare images - it compares the .signature files, 
> and if there's a difference over the threshold, it creates an image of the 
> original and changed file, and then makes a "ghost" version of the change to 
> overlay on the original.  Does this seem correct.  Worth documenting?

Dropping a little paragraph is a good idea, but IMHO it's not worth
documenting it in details, for which interested people should look
directly at the code.

Best,
John