Deep Down the Rabbit Hole: Bash, OverlayFS, and a 30-Year-Old Surprise

Most of the stuff that configure scripts check is obsolete, and breaks in situations like this as the checks are often not workable without running code. It is likely the check does not apply to any system that has existed for decades. Lots of systems have disabled eg Nix in 2017 [1]

[1] https://github.com/NixOS/nixpkgs/commit/dff0ba38a243603534c9...

I had a look at the bash source code a few years back, and there are tons of hacks and workarounds for 1980s-era systems. Looking at the git log, GETCWD_BROKEN was added in bash 1.14 from 1996, presumably to work around some system at the time (a system which was perhaps already old in 1996, but it's not detailed which).

Also, that getcwd.c which contains the getcwd() fallback and bug is in K&R C, which should be a hint at how well maintained all of this is. Bash takes "don't fix it if it ain't broke" to new levels, to the point of introducing breakage like here (the bash-malloc is also notorious for this – no idea why that's still enabled by default).