This seems to have broken buildfarm member guaibasaurus, which I believe is the only one that runs "make dist" as part of the buildfarm. And as a result,t hat breaks the snapshot build uploads.
I don't know exactly how it does it, it appears to not run from within the git repository. It might be this needs an update to the buildfarm code itself to handle this path? I haven't dug into how that code does the make dist part (thus cc:ing in Andrew as well).
This changes "make dist" to directly use "git archive", rather than the custom shell script it currently runs.
This is to make the creation of the distribution tarball more directly traceable to the git repository. That is why we removed the "make distprep" step.
"make dist" continues to produce a .gz and a .bz2 tarball as before.
The archives produced this way are deterministic and reproducible, meaning for a given commit the result file should always be bit-for-bit identical. The exception is that if you use a git version older than 2.38.0, gzip records the platform in the archive, so you'd get a different output on Windows vs. macOS vs. "UNIX" (everything else). In git 2.38.0, this was changed so that everything is recorded as "UNIX" now. This is just something to keep in mind. This issue is specific to the gzip format, it does not affect other compression formats.
Meson has its own distribution building command (meson dist), but we are not using that at this point. The main problem is that, the way they have implemented it, it is not deterministic in the above sense. Also, we want a "make" version for the time being. But the target name "dist" in meson is reserved for that reason, so we call the custom target "pgdist" (so call something like "meson compile -C build pgdist").