System library dependencies not documented

[andreasabel]

Which system libraries does unix depend on? This should be documented in:

• README
• Maybe also unix.cabal via a pkgconfig-depends?

Here is a broken CI run with GHC 9.4 and --enable-executable-static on ubuntu-22.04 that points to a missing library, but it is not apparent from unixs documentation which one:

/usr/local/.ghcup/ghc/9.4.3/lib/ghc-9.4.3/lib/../lib/x86_64-linux-ghc-9.4.3/unix-2.7.3/libHSunix-2.7.3.a(Files.o):
function ghczuwrapperZC1ZCunixzm2zi7zi3ZCSystemziPosixziFilesZCmknod: 
error: undefined reference to '__xmknod'

See https://github.com/andreasabel/ci-executable-static/actions/runs/3620850873/jobs/6103575852

Report at ubuntu-22.04 home:

• ubuntu-22.04 breaks compilation to static executables with GHC 9.4 actions/runner-images#6689

[hasufell]

Which system libraries does unix depend on?

$ lddtree libHSunix-2.7.2.2-ghc8.10.7.so | grep -v libHS                                                                          114ms  Mon 16:49
    librt.so.1 => /lib64/librt.so.1
    libutil.so.1 => /lib64/libutil.so.1
    libdl.so.2 => /lib64/libdl.so.2
    libpthread.so.0 => /lib64/libpthread.so.0
    libgmp.so.10 => /lib64/libgmp.so.10
    libc.so.6 => /lib64/libc.so.6
        ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2
    libm.so.6 => /lib64/libm.so.6

[Bodigrim]

__xmknod is mknod provided by glibc. I don't think the CI failure is anyhow specific to unix package, it's just the very first library GHC is trying to link statically.

[andreasabel]

Thanks for the info.
I think it would be good to add the information that Julian retrieved to the docs, or, alternatively, the recipe how to retrieve it.