On 2022-06-13 at 18:32 -0700, Paul Eggert wrote: > Yes, all that could be done in theory, but it'd take a lot of > hacking and it's been decades and it hasn't happened. > > I'd rather have shell scripts "just work" in parallel with a minimum > of fuss. If this hasn't happened, that might be because nobody found it important enough to dive into such task, relatively to the effort required (or estimated). Everyone wishes their configure scripts to finish quickly but, first and foremost, the result must be right. Something which is easier with serial script than with a parallel implementation. And in the case of configure, they are a mix of boilerplate code, m4 and shell scripting, so not many people would be, in addition to motivated by that task, proficient enough in all of those. Furthermore, configure typically target really classic dialects, which makes even more difficult to use modern features which could speed up the script. Optimizing that at bash would likely be even more complex, since it could only automatically optimize the cases that would never have side effects. I think that most gainings should probably come from autoconf blocks with optimizations. Still, it might be possible through some loadable builtin to improve the configure times. Do you have any handy example of configure that takes too long to run?
