bash formula warns about LC_CTYPE: cannot change locale (): Bad file descriptor

[supriyo-biswas]

Output of brew config

$ brew config 
HOMEBREW_VERSION: 4.5.12
ORIGIN: https://github.com/Homebrew/brew
HEAD: 50fa89e96bccedeca21287427eb7db12289f57ea
Last commit: 2 days ago
Branch: stable
Core tap JSON: 26 Jul 05:39 UTC
Core cask tap JSON: 26 Jul 05:39 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 8
Homebrew Ruby: 3.4.5 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.4.5/bin/ruby
CPU: octa-core 64-bit arm_firestorm_icestorm
Clang: 17.0.0 build 1700
Git: 2.39.5 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.5-arm64
CLT: 16.4.0.0.1.1747106510
Xcode: N/A
Rosetta 2: false

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: Some installed casks are deprecated or disabled.
You should find replacements for the following casks:
  microsoft-remote-desktop

### Description of issue

When launching bash from homebrew, I get the following warning after running each bash command:

$ /opt/homebrew/bin/bash --login
bash: warning: setlocale: LC_CTYPE: cannot change locale (): Bad file descriptor
$ [/opt/homebrew/bin/bash shell]

I've tried toggling the Terminal.app setting under Profiles > Advanced > Set locale environment variables at startup, but the same warning remains.

The issue occurred after a recent upgrade of the brew packages, although I'm unable to recall the previous versions of bash and its dependencies etc.

[carlocab]

Can't reproduce, I'm afraid. What's the output of locale when you run it outside of Homebrew bash?

[httpstorm]

@carlocab
I also started getting a related error since I updated bash from 5.2.37 to 5.3.3 today:

-bash: warning: setlocale: LC_COLLATE: cannot change locale (): No such file or directory

locale
LANG=""
LC_COLLATE="C"
LC_CTYPE="UTF-8"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL=
-bash: warning: setlocale: LC_COLLATE: cannot change locale (): No such file or directory

While the workaround is to set LC_COLLATE or LANG in .profile, by default they are not set, so the new version of bash is broken in the default configuration and needs a fix.

# ~/.profile
export LC_COLLATE=C

System Settings, General, Language & Region, Preferred Languages is set to

• English (UK)
• Bulgarian

[httpstorm]

I also don't set LANG or any of the LC_ environment variables and LANG isn't set by default. I use MacBook Pro 2019 16" Intel, macOS 15.5. One possible explanation is that I have multiple Preferred Languages. Perhaps bash can't decide which one to use?
I noticed that your prompt is % which is common for zsh. The default prompt in bash is $ for user and # for root.

[osalbahr]

You're right, I was on zsh. Maybe I shouldn't assume that the locale environment variables would be the same. I changed Terminal settings to start with command /opt/homebrew/bin/bash and I still have LANG set:

$ echo $0
-bash
$ echo $LANG
en_US.UTF-8

[httpstorm]

I see the following differences:

1. You are using a Mac with Apple silicon, I use Intel
2. You likely have English (US) as the only item under Preferred Languages
3. You have configured Terminal with Command, I have changed the default shell

# Edit /etc/shells
sudo nano /etc/shells

# Add the following line at the end
/usr/local/bin/bash

# Change the default shell to bash, and exit
chsh -s /usr/local/bin/bash

# Note: for Apple silicon, the path to bash is
/opt/homebrew/bin/bash

I use the following Terminal settings:

• General, Shells open with
• Default login shell (selected)
• Profiles, Shell, Startup
• Run command (unchecked)
• Profiles, Advanced, International
  Text encoding = Unicode (UTF-8)

My guess would be 2.
What does it say under System Settings, General, Language & Region, Preferred Languages?

[albgus]

I think this is onto something, and the behaviour might depend on your terminal app as well.

In iTerm 2 I solved the issue by ensuring that Settings -> Profiles -> Terminal -> Environment was set to Set locale environment variables automatically. This sets all the variables to en_US.UTF-8 instead of simply "C"

[httpstorm]

I use the default macOS Terminal. Profiles, Advanced, Set locale environment variables at startup is selected, but the warning occurs. The workaround for me is to add this line to ~/.profile

export LC_COLLATE=C

But this warning should not appear at the default configuration and requires a fix. Preferred Languages is set to

• English (UK) – Primary
• Bulgarian

[lightbulbjim]

Can reproduce:

~ $ echo $SHELL
/usr/local/bin/bash
-bash: warning: setlocale: LC_CTYPE: cannot change locale (): Bad file descriptor

~ $ echo $BASH_VERSION
5.3.3(1)-release
-bash: warning: setlocale: LC_CTYPE: cannot change locale (): Bad file descriptor

~ $ locale
LANG="en_AU.UTF-8"
LC_COLLATE="en_AU.UTF-8"
LC_CTYPE="en_AU.UTF-8"
LC_MESSAGES="en_AU.UTF-8"
LC_MONETARY="en_AU.UTF-8"
LC_NUMERIC="en_AU.UTF-8"
LC_TIME="en_AU.UTF-8"
LC_ALL=
-bash: warning: setlocale: LC_CTYPE: cannot change locale (): Bad file descriptor

And with the stock system Bash:

~ $ /bin/bash

~ $ echo $BASH_VERSION
3.2.57(1)-release

~ $ locale
LANG="en_AU.UTF-8"
LC_COLLATE="en_AU.UTF-8"
LC_CTYPE="en_AU.UTF-8"
LC_MESSAGES="en_AU.UTF-8"
LC_MONETARY="en_AU.UTF-8"
LC_NUMERIC="en_AU.UTF-8"
LC_TIME="en_AU.UTF-8"
LC_ALL=

[fsc-eriker]

The problem in Homebrew Bash seems to be caused by the PROMPT_COMMAND. I don't know why (running the commands in isolation does not produce the warning) but unsetting PROMPT_COMMAND gets rid of the immediate symptom.

[gwd]

FWIW, adding the following to my .bashrc silences the warnings:

eval $(locale)

This effectively sets LC_CTYPE based on whatever the current value of LANG is (and to "C" if it's empty). No idea if this is a good approach or not.

[avoidik]

I have installed https://formulae.brew.sh/formula/bash-completion@2

In my case the problem occurred when I was using a native Terminal app:

-bash: warning: setlocale: LC_COLLATE: cannot change locale (): No such file or directory

I was able to narrow it down to this line here:

https://github.com/scop/bash-completion/blob/c55ee7f6fb75300786cb522261f68eb80366c41f/bash_completion#L357

It's trying to set this property:

++++ local LC_COLLATE=C LC_CTYPE=en_US.UTF-8 LC_ALL=

Which is obviously invalid. The fix for me was adding these lines to ~/.bashrc:

if [[ -z "$LC_ALL" ]]; then
  export LC_ALL='en_US.UTF-8'
fi

if [[ -f "${HOMEBREW_PREFIX}/etc/profile.d/bash_completion.sh" ]]; then
  LC_COLLATE=C LANG= LC_CTYPE=C source "${HOMEBREW_PREFIX}/etc/profile.d/bash_completion.sh"
fi

[fsc-eriker]

I reported the same bug against bash-completion yesterday, but investigations so far seem to indicate a problem in Bash itself. scop/bash-completion#1486

That's still work in progress; but a a brief summary of what I'm thinking, the output of locale is clearly not the whole story. The output from defaults read -g AppleLocale displays a funky and I think nonstandard value, apparently because the system is set up with English but a geography where English is not the default (I can only guess about what the boundaries are; I would have expected Australia to be fine, but maybe @lightbulbjim has the same problem? But Finland and Japan clearly cause this issue). I speculate that this AppleLocale value gets consulted at some point and might contribute to the problem.

The OS version also plays a role; on Sonoma I can reproduce a segmentation fault but this seems to be fixed in Sequoia, with the same version of Bash from Homebrew.

[httpstorm]

My languages are English UK and Bulgarian. I don't think en_BG is a valid locale

defaults read -g AppleLocale
en_BG

Workaround:

# ~/.profile
export LC_COLLATE=C