3 ms·

> Incremental compilation is much harder to achieve when you require bit-for-bit identical output Presumably, incremental compilation is only for development.

> Incremental compilation is much harder to achieve when you require bit-for-bit identical output Presumably, incremental compilation is only for development. For release, you would do a clean build, which would be reproducible. > Even just stripping your compile paths from debug info is not entirely straightforward Just use the same paths.

mananaysiempre 5y ago
> Presumably, incremental compilation is only for development. For release, you would do a clean build, which would be reproducible. I’d say that’s exactly the wrong approach: given how hard incremental anything is, it would make sense to insist on bit-exact output and then fuzz the everliving crap out of it until bit-exactness was reached. (The GCC maintainers do not agree.) But yes, you could do that. It’s not impossible to do reproducible builds with GCC 4.7 or whatever, it’s just intensely unpleasant, especially as a distro maintainer faced with yet another bespoke build system. (Saying that with all the self-awareness of a person making their own build system.) > Just use the same paths. I mean, sure, but then you have to build and debug in a chroot and waste half a day of your life figuring out how to do that and just generally feel stupid. And your debug info is still useless to anybody not using the exact same setup. Can’t we just embed relative paths instead, or even arbitrary prefixes it the code is coming from more than one place? In recent GCC versions we can, just chuck the right incantation into CPPFLAGS and you’re golden. All of this is not really difficult except insofar as getting a large and complicated program to do anything is difficult. (Stares in the direction of the 17-year-old Firefox bug for XDG basedir support.) That’s why I said it wasn’t a GCC problem so much as a maintainer attitude problem.

mananaysiempre 5y ago

> Presumably, incremental compilation is only for development. For release, you would do a clean build, which would be reproducible. I’d say that’s exactly the wrong approach: given how hard incremental anything is, it would make sense to insist on bit-exact output and then fuzz the everliving crap out of it until bit-exactness was reached. (The GCC maintainers do not agree.) But yes, you could do that. It’s not impossible to do reproducible builds with GCC 4.7 or whatever, it’s just intensely unpleasant, especially as a distro maintainer faced with yet another bespoke build system. (Saying that with all the self-awareness of a person making their own build system.) > Just use the same paths. I mean, sure, but then you have to build and debug in a chroot and waste half a day of your life figuring out how to do that and just generally feel stupid. And your debug info is still useless to anybody not using the exact same setup. Can’t we just embed relative paths instead, or even arbitrary prefixes it the code is coming from more than one place? In recent GCC versions we can, just chuck the right incantation into CPPFLAGS and you’re golden. All of this is not really difficult except insofar as getting a large and complicated program to do anything is difficult. (Stares in the direction of the 17-year-old Firefox bug for XDG basedir support.) That’s why I said it wasn’t a GCC problem so much as a maintainer attitude problem.