Developers build stuff from VCS checkouts. But the package managers and ports systems that regular users rely upon, still use tarball releases, not VCS checkout

Developers build stuff from VCS checkouts. But the package managers and ports systems that regular users rely upon, still use tarball releases, not VCS checkouts, as their upstreams. For example: Homebrew. If you tell Homebrew to --build-from-source, it'll pull down a release tarball from its release URL; unpack it; set up the shell environment just so; and then run the same very same ./configure script the upstream generated with Autotools. It'd actually be kind of a problematic bootstrapping problem if that ./configure script did require Autotools to run, as there's no real legal way for (proprietary) macOS to ship (GNU, GPLv3) Autotools. And that's much the same problem many other proprietary UNIXes were in, back when: wanting to support "standard" tooling, but being too wary of this new "copyleft" thing to be willing to ship any GPLed software as part of their OS. Thus, the broadest industry support came out for the tooling that doesn't force the upstream's tooling's licensing choices on the downstream. (Ironically, that tooling happened to be from GNU, the precise people whose software they were trying to avoid shipping.)