Comment by IshKebab 18 hours ago
I don't think it's fair to say "because they are lazy or don't understand". Who would want to understand that mess? It isn't a virtue.
A fairer criticism would be that they have no sense to use a more sane build system. CMake is a mess but even that is faaaaar saner than autotools, and probably more popular at this point.
Autotools use M4 to meta-program a bash script that meta-programs a bunch of C(++) sources and generates C(++) sources that utilizes meta-programming for different configurations; after which the meta-programmed script, again, meta-programs monolithic makefiles.
This is peak engineering.
> CMake is a mess but even that is faaaaar saner than autotools, and probably more popular at this point.
Having done a deep dive into CMake I actually kinda like it (really modern cmake is actually very nice, except the DSL but that probably isn't changing any time soon), but that is also the problem: I had to do a deep dive into learning it.
My experience with cmake, though dated, is that it's simpler because it simply cannot do what autotools can do.
It really smelled of "oh I can do this better", and you rewrite it, and as part of rewriting it you realise oh, this is why the previous solution was complicated. It's because the problem is actually more complex than I though.
And then of course there's the problem where you need to install on an old release. But the thing you want to install requires a newer cmake (autotools doesn't have this problem because it's self contained). But this is an old system that you cannot upgrade, because the vendor support contract for what the server runs would be invalidated. So now you're down a rabbit hole of trying to get a new version of cmake to build on an unsupported system. Sigh. It's less work to just try to construct `gcc` commands yourself, even for a medium sized project. Either way, this is now your whole day, or whole week.
If only the project had used autotools.
No, CMake can do everything Autotools does, but a hell of a lot simpler and without checking for a gazillion flags and files that you don't actually need to but you're checking them anyway because you copied the script from a someone who copied the script from... all the way back to the 90s when C compilers actually existed that didn't have stdint.h or whatever.
CMake is easy to upgrade. There are binary downloads. You can even install it with pip (although recently the Python people in their usual wisdom have broken that).
CMake can't do everything autotools does, but the stuff autotools does which CMake doesn't isn't relevant anymore in today's world.
The fundamental curse of build systems is that they are inherently complex beasts that hardly anybody has to work with full-time, and so hardly anybody learns them to the necessary level of detail.
The only way out of this is to simplify the problem space. Sometimes for real (by reducing the number of operating systems and CPU architectures that are relevant -- e.g. CMake vs. Autotools) and sometimes by somewhat artificially restricting yourself to a specific niche (e.g. Cargo).
Correct. I avoid autotools and cmake as much as I can. I'd better write Makefiles by hand. But when I need to deal with them, I'd prefer cmake. I can can modify CMakeLists.txt in a meaningful way and get the results I want. I wouldn't touch autotools build system because I never was able to figure out which of the files is the configuration that is meant to be edited by hands and not generated by scripts in other files. I tried to dig the documentation but I never made it.
I took the trouble (and even spent the money) to get to grips with autotools in a structured and detailed way by buying a book [1] about it and reading as much as possible. Yes, it's not trivial, but autotools are not witchcraft either, but as written elsewhere, a masterpiece of engineering. I have dealt with it without prejudice and since then I have been more of a fan of autotools than a hater. Anyway, I highly recommend the book and yes, after reading it, I think autotools is better than its reputation.
[1] https://nostarch.com/autotools2e