Re: Regression tests fail with musl libc because libpq.so can't be loaded

Thomas Munro:
> I'd look into whether there is a difference in the rules it uses for
> deciding not to trust LD_LIBRARY_PATH, which seems to be around here
> somewhere:
>
> https://github.com/bminor/musl/blob/7ada6dde6f9dc6a2836c3d92c2f762d35fd229e0/ldso/dynlink.c#L1812

Yeah, I have been looking at that, too. I had also experimented a bit
with setuid/setgid for that matter, but that didn't lead anywhere, yet.
I'm not 100% sure, but I think this would also not match my other
observation, that LD_LIBRARY_PATH does work for libpqwalreceiver (direct
dep), but not libpq (indirect dep).

> Another interesting thing that came up when I googled musl/glibc
> differences -- old but looks plausibly still true (not that I expect
> our code to be modifying that stuff in place, just something to
> check):
>
> https://www.openwall.com/lists/musl/2014/08/31/14

To me, this seems very much like what could happen - it matches all my
observations, so far. But I can't tell how likely that is, not knowing
much of the postgres code.

Best,

Wolfgang