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

Bruce Momjian:
>> The library/postgres docker image has been pulled about 8 billion times
>> since 2014 [1]. While we can't really tell how many of those pulled the
>> alpine variant of the image, comparing the alpine [2] and ubuntu/debian
>> [3,4] base images gives a rough estimate of >50% using alpine in general.
> 
> Uh, what is the current behavior of Postgres on musl?  It just fails if
> the process title is longer than argv[0] plus the environment space to
> the LD_ environment variable, and then linking fails for certain
> extensions?  If there are many downloads, why would we only be getting
> this report now?

The process title works fine. It's just the way how space is cleared for 
the process title, that is causing problems elsewhere.

The thing that is broken when running postgres on alpine/musl is, to put 
libpq in a custom path and use LD_LIBRARY_PATH to find it when loading 
libpqwalreceiver (+ some contrib modules). Nobody does that, especially 
not in a container environment where postgres is likely the only thing 
running in that container, so there is no point in using any custom 
library paths or anything - the image is built once and made to work, 
and everybody else is just using that working image.

The much more practical problem is that the test suite doesn't run, 
because it makes use of LD_LIBRARY_PATH for that purpose. In the past, 
the packagers for alpine only disabled the failing tests, but IIRC they 
have given up on that and just disabled the whole test suite by now.

Best,

Wolfgang