zlib-ng not used on fedora 40

[PhilipDeegan]

Background information

What version of the PMIx Reference Library are you using?

major=5
minor=0
release=2

Describe how PMIx was installed

indirectly via openmpi v5.0.3

Please describe the system on which you are running

• Operating system/version: fedora 40
• Computer hardware: amd cpu (not relevant)
• Network type: N/A

---

Details of the problem

Trying to use mpirun results in

PMIx was unable to find a usable compression library
on the system. We will therefore be unable to compress
large data streams. This may result in longer-than-normal
startup times and larger memory footprints. We will
continue, but strongly recommend installing zlib or
a comparable compression library for better user experience.

You can suppress this warning by adding "pcompress_base_silence_warning=1"
to your PMIx MCA default parameter file, or by adding
"PMIX_MCA_pcompress_base_silence_warning=1" to your environment.

zlib-ng is installed as zlib is deprecated in fedora 40

/usr/include/zlib-ng.h
/usr/include/zlib_name_mangling-ng.h
/usr/lib64/libz.so.1.3.0.zlib-ng
/usr/lib64/cmake/zlib-ng

[rhc54]

No idea what zlib-ng is nor why someone deprecated zlib, but the message explains how to suppress the warning. I will put looking into this other library on the list of things to consider down the road - not likely until end of year or probably sometime next year.

[PhilipDeegan]

No idea what zlib-ng

https://github.com/zlib-ng/zlib-ng

why someone deprecated zlib

https://fedoraproject.org/wiki/Changes/ZlibNGTransition

[rhc54]

Okay, nice to know - looks like something only relevant to Fedora 40 and above, so would need some special configure logic changes. As I said, low priority but will eventually get to it.

Or if someone wants it faster, then please post a PR and I'm happy to consider it!

[ggouaillardet]

For the time being, can't you simply install the zlib-ng-compat-devel package and rebuild openpmix?

[PhilipDeegan]

I would expect that should work yes