configure-system-libraries.sh: Skip 32bit libraries during lookup on x64 Linux. #21353

[tinix0]

Fixes #21353
When looking up system libraries on x64 Linux, there might be 32bit libraries present higher on the path priority list than 64bit libraries. These should be skipped, since there is no official 32bit build of .NET 6 for Linux.

Tested on OpenSuse Tumbleweed.

[anvilvapre]

1. uname, arch are part of binutils. readelf is part of binutils. the last is not installed by default (on at least ubuntu). perhaps you could use file on the resolved symlink to the so.
2. is arch (and readelf) available on macos? would be good if someone tests the script there.
3. you now call uname and arch for each match. before calling the function there is also already a check on OS. wouldn't it be better to just to the arch check there as well and pass one additional function arguments to indicate the OS and arch.
4. couldn't a simpler approach be to just call the patch_config function with only 64bit search dirs on 64 bit platforms? this was the readelf check is no longer needed? assuming 64 bit so files are always in lib64 dirs?

[anvilvapre]

i believe there is also a matching issue for this. perhaps you can try to link it. i.e. resolves #issueid.

[tinix0]

1. uname, arch are part of binutils. readelf is part of binutils. the last is not installed by default (on at least ubuntu). perhaps you could use file on the resolved symlink to the so.

   2. is arch (and readelf) available on macos? would be good if someone tests the script there.

   3. you now call uname and arch for each match. before calling the function there is also already a check on OS. wouldn't it be better to just to the arch check there as well and pass one additional function arguments to indicate the OS and arch.

   4. couldn't a simpler approach be to just call the patch_config function with only 64bit search dirs on 64 bit platforms? this was the readelf check is no longer needed? assuming 64 bit so files are always in lib64 dirs?

1. Possibly, but the output is less deterministic.
2. The script already uses arch in darwin path. readelf is not required to be present, its under an linux if statement after all. I do own a Mac and can check it.
3. You are right it would be better to check only once
4. 64bit files might not always be in /lib64, IIRC some distributions put them directly into /lib.

i believe there is also a matching issue for this. perhaps you can try to link it. i.e. resolves #issueid.

I forgot Github does not reference issues from name.