Hi, I think this is reasonable, but I would really appreciate patches for autopkgtest.
Cheers, Ondrej On Mon, 25 Sep 2017 at 04:51 Jiri Palecek <jpale...@web.de> wrote: > Hello, > > I was looking at the recent FTBFS of libgd2, which prevented security > fixes to reach debian archive for more than a week. The FTBFS were > restricted to several architectures. > > By the look of it, it seems that the errors are simple arithmetical > inaccuracies, when the tests expect pixel-exact results. I was > specifically concerned about gdimagerotate/bug00067 test on i386, and > the result of the rotate operation, while not comparing equal to the > expected image, seemed the same to the naked eye. > > Slight differences of the computations on different architectures are to > be expected, eg. if those architectures use different floating point > formats, although it shouldn't matter that much in the test I mentioned > (by rough estimate it should need a precision of about 1/2^18 -- 1/2^20, > while IEE754 float is more precise than that). However, I was surprised > that when I tested it with optimizations turned off, there were failures > in the test suite too, but _different_ failures. This should mean > there's something dodgy going on either in gcc or in the code. > > Anyway, I guess libgd2's aim isn't to provide pixel perfect image > manipulations, but rather accessible image functions for eg. web servers > in PHP. In that case, the testsuite doesn't really reflect the > requirements it should fulfill, and it should focus more on security > than accuracy. > > I would propose to ditch the testsuite completely from the building > process of the package, since in its present state, it is inherently > unreliable and would cause FTBFS. Instead, an autopkgtest testsuite > could be made (with the running the same tests), which could be > automatically ran using ci.debian.org. Such a testsuite could probably > even be rigged to run under valgrind, which could catch some memory > errors. At the same time, the testsuite could be made more lenient (or > the library code more accurate), but that would require substantially > more work and I don't know whether it would be desirable. > > Please let me know what you think. > > Regards > > Jiri Palecek > > -- > pkg-GD-devel mailing list > pkg-gd-de...@lists.alioth.debian.org > http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-gd-devel -- Ondřej Surý <ond...@sury.org>