"I have no name" on RHEL8 Homebrew "bash" and glibc linking issues too

[jamesrtnz]

Additional Info

• I am using Windows Subsystem for Linux

Output of brew config

$ brew config
HOMEBREW_VERSION: 4.6.6
ORIGIN: https://github.com/Homebrew/brew
HEAD: 7878c73b8562eb369f9da66d4c55b89ff6397182
Last commit: 2 days ago
Branch: stable
Core tap JSON: 24 Aug 23:42 UTC
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 4
http_proxy: http://localhost:3128/
https_proxy: http://localhost:3128/
no_proxy: localhost,127.0.0.0/24,10.0.0.0/8,192.168.0.0/16
Homebrew Ruby: 3.4.5 => /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/vendor/portable-ruby/3.4.5/bin/ruby
CPU: quad-core 64-bit zen2
Clang: N/A
Git: 2.43.7 => /bin/git
Curl: 7.61.1 => /bin/curl
Kernel: Linux 4.18.0-553.64.1.el8_10.x86_64 x86_64 GNU/Linux
OS: Red Hat Enterprise Linux release 8.10 (Ootpa) (Ootpa)
Host glibc: 2.28
/usr/bin/gcc: 8.5.0
/usr/bin/ruby: N/A
glibc: 2.35_1
gcc@11: N/A
gcc: 15.1.0
xorg: N/A

Output of brew doctor

$ brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Your system glibc 2.28 is too old.
We will need to automatically install a newer version.

We recommend updating to a newer version via your distribution's
package manager, upgrading your distribution to the latest version,
or changing distributions.

This is a Tier 2 configuration:
  https://docs.brew.sh/Support-Tiers#tier-2
You can report Tier 2 unrelated issues to Homebrew/* repositories!
Read the above document instead before opening any issues or PRs.

Description of issue

The standard OS configuration at my workplace involves a third-party software stack to integrate Active Directory based user accounts into the RHEL environment; as such, my user account comes from Windows AD, and does not exist in /etc/passwd. Standard OS-supplied bash is perfectly happy with this.

Homebrew's "bash", however, reports "I have no name!" when trying to resolve my standard PS1 prompt "[\u@\h]\w\$ " (this isn't a rocket-science prompt):

$ bash
[I have no name!@hostname]~$

It will work if I add my username to /etc/passwd manually; but I didn't expect I'd need to.

On a potentially related note, the HomeBrew "bash" doesn't appear to be picking up the HomeBrew glibc runtime either:

$ ldd /home/linuxbrew/.linuxbrew/bin/bash
/home/linuxbrew/.linuxbrew/bin/bash: /lib64/libc.so.6: version `GLIBC_2.33' not found (required by /home/linuxbrew/.linuxbrew/bin/bash)
/home/linuxbrew/.linuxbrew/bin/bash: /lib64/libc.so.6: version `GLIBC_2.34' not found (required by /home/linuxbrew/.linuxbrew/bin/bash)
/home/linuxbrew/.linuxbrew/bin/bash: /lib64/libc.so.6: version `GLIBC_2.33' not found (required by /home/linuxbrew/.linuxbrew/opt/readline/lib/libreadline.so.8)
/home/linuxbrew/.linuxbrew/bin/bash: /lib64/libc.so.6: version `GLIBC_2.33' not found (required by /home/linuxbrew/.linuxbrew/opt/ncurses/lib/libncursesw.so.6)
	linux-vdso.so.1 (0x00007ffd8cd2b000)
	libreadline.so.8 => /home/linuxbrew/.linuxbrew/opt/readline/lib/libreadline.so.8 (0x00007f561c767000)
	libc.so.6 => /lib64/libc.so.6 (0x00007f561c2ff000)
	libncursesw.so.6 => /home/linuxbrew/.linuxbrew/opt/ncurses/lib/libncursesw.so.6 (0x00007f561c280000)
	/home/linuxbrew/.linuxbrew/lib/ld.so => /lib64/ld-linux-x86-64.so.2 (0x00007f561c6d6000)
$ brew list | grep glibc
glibc
$ find /home/linuxbrew/ -name libc.so.6
/home/linuxbrew/.linuxbrew/Cellar/glibc/2.35_1/lib/libc.so.6

The "brew config" output above does list the updated glibc:
glibc: 2.35_1

Corporate standard OS build; so my options for updating are limited and RHEL8 won't have a later vendor-supported GLIBC build...

Any idea why homebrew's bash RPATH doesn't include homebrew's glibc; or reasons why username resolution isn't working as expected?

[jamesrtnz]

And solving my own problem...

For anyone's future reference, if this is picked up by search; then:

• Create a custom file in /home/linuxbrew/.linuxbrew/etc/ld.so.conf.d specifying the 3rd party software's "nss" library
• brew postinstall glibc

bash now resolves username correct in PS1 prompt.

The question about glibc linking was due to a misinterpretation of ldd; best to ensure homebrew's glibc/bin is on the path to ensure homebrew's ldd is used:

export PATH="/homebrew/linuxbrew/.linuxbrew/bin:$PATH"

Better looking ldd output now:

$ ldd `which bash`
	linux-vdso.so.1 (0x00007ffe8c9b3000)
	libreadline.so.8 => /home/linuxbrew/.linuxbrew/opt/readline/lib/libreadline.so.8 (0x00007f417f286000)
	libc.so.6 => /home/linuxbrew/.linuxbrew/opt/glibc/lib/libc.so.6 (0x00007f417f073000)
	libncursesw.so.6 => /home/linuxbrew/.linuxbrew/opt/ncurses/lib/libncursesw.so.6 (0x00007f417eff4000)
	/home/linuxbrew/.linuxbrew/lib/ld.so => /home/linuxbrew/.linuxbrew/Cellar/glibc/2.35_1/lib64/ld-linux-x86-64.so.2 (0x00007f417f424000)