linux/diagnostic: check `LD_LIBRARY_PATH` when `glibc` is installed.

[carlocab]

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Adding $HOMEBREW_PREFIX/lib to LD_LIBRARY_PATH breaks many things when glibc is installed, so let's make sure brew doctor complains about it.

Closes Homebrew/homebrew-core#109893.

[BrewTestBot]

Review period will end on 2022-09-09 at 06:40:48 UTC.

[carlocab]

I'm not sure how to test this, since, when I do:

linuxbrew@15eb76ba36ac:~/.linuxbrew/Homebrew$ LD_LIBRARY_PATH=$(brew --prefix)/lib brew doctor
/bin/bash: relocation error: /home/linuxbrew/.linuxbrew/lib/libc.so.6: symbol _dl_audit_preinit, version GLIBC_PRIVATE not defined in file ld-linux-x86-64.so.2 with link time reference

[BrewTestBot]

Review period ended.

[XuehaiPan]

The original issue Homebrew/homebrew-core#109893 is resolved by #13873. Now we should check that etc/ld.so.conf and etc/ld.so.conf.d/*.conf do not point outside HOMEBREW_PREFIX.

• https://github.com/Homebrew/brew/pull/13873
• https://github.com/Homebrew/homebrew-core/pull/109998

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.