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.__________________________________________________________.
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| Many Free software and/or Open Source projects this day  |
| and age are switching away from old tried and true tools |
| such as GNU auto tools to meson.                         |
|                                                          |
| This phenomenon isn't particularly new, if you've been   |
| around for a while, you'll remember this happened before |
| with jam and then, notably, with cmake.                  |
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| Meson being the latest fad in build systems however, is  |
| particularly annoying if you're fond of more esoteric    |
| platforms, old or new, because it depends on python, and |
| it's ecosystem, and a rather new-ish version at that.    |
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| I always found the python ecosystem to be particularly   |
| fragile, as they don't care much about keeping backwards |
| compatibility between versions. And now that projects    |
| don't even care to make things work with OS package      |
| managers anymore, and instead, their build instructions  |
| mention 'just' grab <long list of dependencies> from pip |
| / pypi, getting reliably reproducible builds for these   |
| things is harder than ever. As such, I'm finding this    |
| latest meson fad particularly problematic.               |
|                                                          |
| Meson promises to make things "easier" on developers, by |
| being on the surface, 'simple', but everyone who's done  |
| this for a while knows that 'simple' usually means worse |
| in practice, and I believe this holds true for Meson.    |
|                                                          |
| Even during the previous autotools exoduses, I always    |
| felt a bit like we were collectively making a mistake,   |
| because the proposed alternatives were missing something |
| important.                                               |
|                                                          |
| Autotools helps you in writing cross-platform software   |
| by scanning your source files for platform-specific      |
| things, and letting you know you probably ought to add   |
| a configure check for those. It can then also output a   |
| config.h file with definitions for things which are and  |
| are not present on the current platform, such that you   |
| may provide alternative implementations within your      |
| source code.                                             |
|                                                          |
| If I run `autoscan`, for example, in the fvwm3 project   |
| root, it comes up with the following:                    |
|                                                          |
|     configure.ac: warning: missing                       |
|     AC_CHECK_FUNCS([gethostname]) wanted                 |
|     by: fvwm/fvwm3.c:2171                                |
|                                                          |
| What it's complaining about here, is that in fvwm3.c the |
| gethostname() function is used, which is a platform-     |
| specific function that may not be present on all systems.|
|                                                          |
| It has similar warnings for many other functions used    |
| throughout the project.                                  |
|                                                          |
| Not all checks are about functions, they can be about    |
| architecture specific things, like endianness, etc,...   |
|                                                          |
| So, you can see, the autotools strategy towards helping  |
| you write portable software is not hardcoded platform    |
| names like you see in many projects, like the old        |
| ubiquious #ifdef __WIN32 or #ifdef __FreeBSD__ etc, but  |
| rather, granular checks for individual features and      |
| platform characteristics.                                |
|                                                          |
| The benefit of this approach is that not only does it    |
| give your software a fighting chance to run on more      |
| platforms, it also gives more descriptive errors for     |
| other developers looking to port your software to their  |
| platform.                                                |
|                                                          |
| These days, most developers don't care if their software |
| runs on more than just GNU+Linux/Windows/Mac, and maybe  |
| the BSD's if you're lucky. And it seems, people have     |
| written off autotools as some archaic boomer tool.       |
|                                                          |
| While M4 might not be the prettiest language to write    |
| your platform checks in, I think the approach used by    |
| autotools is the correct one, and I haven't seen a build |
| system with an equivalent system. This isn't just about  |
| supporting ancient legacy platforms, but also new ones.  |
| If I were to write a new OS tomorrow, these platform     |
| checks would be just as valid for my new OS as they are  |
| for the ancient platforms. It's just the sane, correct   |
| approach to writing portable software.                   |
|                                                          |
| Yes, you can manually write these checks in cmake or in  |
| meson, as these build systems do have ways to check if a |
| particular function is present, or if a particular       |
| header is present, but none of them have these checks    |
| built-in, in the way autotools has them, and none come   |
| with a tool equivalent to `autoscan`, which means that   |
| you won't even KNOW which checks you're missing in your  |
| software.                                                |
|                                                          |
| I can tell you autoscan has warned me about stuff I      |
| hadn't even CONSIDERED to be a potential porting issue.  |
| It is extremely helpful. There is so much historical     |
| knowledge contained within these tools, I sincerely      |
| believe that we as developers ought to think twice       |
| before throwing out the baby with the bath water.        |
|                                                          |
| If you're writing proprietary software, where you're     |
| targetting only very specific supported platforms, none  |
| of this really matters, and of course, meson or cmake    |
| seem more than fine. And I think what we've been seeing  |
| over the past decade or so is an influx of developers    |
| who came from that world primarily, and get weirded out  |
| by the tooling in the Free software community, and bring |
| their pushy politics with them, for whatever they do not |
| understand surely must be bad and ought to be shunned.   |
|                                                          |
| Of course, everything gravitating towards monoculture    |
| doesn't help. Many developers aren't even aware that     |
| other platforms even exist. And while this problem has   |
| been a thing for a while now, I find that meson          |
| depending on python just made the problem so much worse  |
| once again.                                              |
|                                                          |
| But I also found that many people aren't aware of these  |
| issues or understand how autotools is intended to work,  |
| so I hope this helped someone out there understand! :)   |
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