[Bug Report] `_comp_expand_glob` may cause Bash warning about `cannot change locale` on macOS

[RainmanVi]

Update (2025-09-23):

It turns out the issue was related to the region settings. I had English (US) as the primary language with the region set to Japan. After changing the region to the United States, the problem was resolved. Switching it back to Japan reproduced the issue.

---

Describe the bug

Each time I start a new bash session, the following warning is prompted:

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

After debugging it using PS4='+ $BASH_SOURCE:$LINENO:' bash -xlic "", I found the issues are related to bash-completion@2 in the output:

+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:372:(( 5 ))
bash: warning: setlocale: LC_COLLATE: cannot change locale (): No such file or directory

+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:372:(( 1 ))
bash: warning: setlocale: LC_COLLATE: cannot change locale (): No such file or directory

More detailed log

++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3439:for compat_dir in "${compat_dirs[@]}"
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3440:[[ -d /opt/homebrew/etc/bash_completion.d ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3440:[[ -r /opt/homebrew/etc/bash_completion.d ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3440:[[ -x /opt/homebrew/etc/bash_completion.d ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3441:local compat_files
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3442:_comp_expand_glob compat_files '"$compat_dir"/*'
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:334:(( 2 != 2 ))
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:338:[[ compat_files == @(GLOBIGNORE|GLOBSORT|_*|*[^_a-zA-Z0-9]*|[0-9]*|) ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:344:local _original_opts=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:345:set +o noglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:346:shopt -s nullglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:347:shopt -u failglob dotglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:351:local GLOBIGNORE= GLOBSORT=name
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:355:local LC_COLLATE=C LC_CTYPE=en_US.UTF-8 LC_ALL=
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:357:eval -- 'compat_files=()'
+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:357:compat_files=()
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:358:eval -- 'compat_files=("$compat_dir"/*)'
+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:358:compat_files=("$compat_dir"/*)
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:363:_comp_unlocal GLOBIGNORE
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:251:(( BASH_VERSINFO[0] >= 5 ))
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:251:shopt -q localvar_unset
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:256:unset -v GLOBIGNORE
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:364:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:dotglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:367:shopt -u dotglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:369:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:nullglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:369:shopt -u nullglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:370:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:failglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:371:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:noglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:372:eval '((${#compat_files[@]}))'
+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:372:(( 5 ))
bash: warning: setlocale: LC_COLLATE: cannot change locale (): No such file or directory
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3443:local compat_file
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3444:for compat_file in "${compat_files[@]}"
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ 000_bash_completion_compat.bash != @(@(#*#|*@(~|.@(bak|orig|rej|swp|@(dpkg|ucf)-*|rpm@(orig|new|save))))|Makefile*|) ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -f /opt/homebrew/etc/bash_completion.d/000_bash_completion_compat.bash ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -r /opt/homebrew/etc/bash_completion.d/000_bash_completion_compat.bash ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3447:_comp__init_startup_configs+=("$compat_file")
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3444:for compat_file in "${compat_files[@]}"
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ brew != @(@(#*#|*@(~|.@(bak|orig|rej|swp|@(dpkg|ucf)-*|rpm@(orig|new|save))))|Makefile*|) ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -f /opt/homebrew/etc/bash_completion.d/brew ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -r /opt/homebrew/etc/bash_completion.d/brew ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3447:_comp__init_startup_configs+=("$compat_file")
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3444:for compat_file in "${compat_files[@]}"
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ git-completion.bash != @(@(#*#|*@(~|.@(bak|orig|rej|swp|@(dpkg|ucf)-*|rpm@(orig|new|save))))|Makefile*|) ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -f /opt/homebrew/etc/bash_completion.d/git-completion.bash ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -r /opt/homebrew/etc/bash_completion.d/git-completion.bash ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3447:_comp__init_startup_configs+=("$compat_file")
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3444:for compat_file in "${compat_files[@]}"
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ git-prompt.sh != @(@(#*#|*@(~|.@(bak|orig|rej|swp|@(dpkg|ucf)-*|rpm@(orig|new|save))))|Makefile*|) ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -f /opt/homebrew/etc/bash_completion.d/git-prompt.sh ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -r /opt/homebrew/etc/bash_completion.d/git-prompt.sh ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3447:_comp__init_startup_configs+=("$compat_file")
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3444:for compat_file in "${compat_files[@]}"
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ tmux != @(@(#*#|*@(~|.@(bak|orig|rej|swp|@(dpkg|ucf)-*|rpm@(orig|new|save))))|Makefile*|) ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -f /opt/homebrew/etc/bash_completion.d/tmux ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3446:[[ -r /opt/homebrew/etc/bash_completion.d/tmux ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3447:_comp__init_startup_configs+=("$compat_file")
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3439:for compat_dir in "${compat_dirs[@]}"
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3440:[[ -d /opt/homebrew/Cellar/bash-completion@2/2.16.0/etc/bash_completion.d ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3440:[[ -r /opt/homebrew/Cellar/bash-completion@2/2.16.0/etc/bash_completion.d ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3440:[[ -x /opt/homebrew/Cellar/bash-completion@2/2.16.0/etc/bash_completion.d ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3441:local compat_files
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3442:_comp_expand_glob compat_files '"$compat_dir"/*'
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:334:(( 2 != 2 ))
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:338:[[ compat_files == @(GLOBIGNORE|GLOBSORT|_*|*[^_a-zA-Z0-9]*|[0-9]*|) ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:344:local _original_opts=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:345:set +o noglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:346:shopt -s nullglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:347:shopt -u failglob dotglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:351:local GLOBIGNORE= GLOBSORT=name
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:355:local LC_COLLATE=C LC_CTYPE=en_US.UTF-8 LC_ALL=
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:357:eval -- 'compat_files=()'
+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:357:compat_files=()
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:358:eval -- 'compat_files=("$compat_dir"/*)'
+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:358:compat_files=("$compat_dir"/*)
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:363:_comp_unlocal GLOBIGNORE
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:251:(( BASH_VERSINFO[0] >= 5 ))
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:251:shopt -q localvar_unset
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:256:unset -v GLOBIGNORE
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:364:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:dotglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:367:shopt -u dotglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:369:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:nullglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:369:shopt -u nullglob
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:370:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:failglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:371:[[ :braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor:xtrace:checkwinsize:cmdhist:complete_fullquote:expand_aliases:extglob:extquote:force_fignore:globasciiranges:globskipdots:interactive_comments:login_shell:patsub_replacement:progcomp:promptvars:sourcepath: == *:noglob:* ]]
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:372:eval '((${#compat_files[@]}))'
+++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:372:(( 1 ))
bash: warning: setlocale: LC_COLLATE: cannot change locale (): No such file or directory
++++ /opt/homebrew/Cellar/bash-completion@2/2.16.0/share/bash-completion/bash_completion:3443:local compat_file

To reproduce

After making the /opt/homebrew/bin/bash the default shell via chsh -s /opt/homebrew/bin/bash, just open the Terminal app installed by default on macOS, then the Bash warning is prompted. The warning will disappear if I uninstall the bash-completion@2.

Expected behavior

There is no Bash warning every time a new bash session is created.

Versions (please complete the following information)

• Operating system name/distribution and version: macOS Sonoma 14.8 (Apple M3)
• bash version, echo "$BASH_VERSION": GNU bash, version 5.3.3(1)-release (aarch64-apple-darwin23.6.0)
• bash-completion version, (IFS=.; echo "${BASH_COMPLETION_VERSINFO[*]}"): 2.16.0
• Homebrew version: Homebrew 4.6.11

Additional context

I use the default Terminal app and the Bash installed via Homebrew as the default shell on macOS:

/opt/homebrew/bin/brew install bash bash-completion@2 coreutils findutils gnu-sed grep

Debug trace

See above, More detailed log.

[akinomyoga]

That seems strange. The error message is produced here, and it happens when this line fails. Based on the error message, setlocale(LC_COLLATE, ""); is failling. However, the POSIX standard requires setlocale to accept an empty string "".

This line LC_ALL= was first included in release 2.15.0, but we haven't received a similar report until now. It implies that macOS Sonoma 14.8 has changed something, or the locale settings of the reporter's environment are incomplete. Does anyone else using macOS 14.8 experience the same warning messages?

[RainmanVi]

@akinomyoga Thank you for your timely response. In fact, I came across this issue when I was using a 14.6 or lower version of macOS. Then I tried to update it to the current latest 14.8, but it didn't help.

Any other methods to test if setlocale works as expected? My result is:

$ locale -a | grep -e '^C$' -e '^en_US'
en_US.US-ASCII
en_US.UTF-8
en_US
en_US.ISO8859-15
en_US.ISO8859-1
C

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

I also tried to disable the Terminal app setting Set locale environment variables on startup (Terminal -> Settings... -> Profiles -> Advanced -> International) but it didn't help either and got worse:

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

[akinomyoga]

$ locale
LANG=""

This is unusual. When "" is specified to setlocale for the category LC_COLLATE, the system is supposed to look LC_ALL, LC_COLLATE, and LANG as a fallback. When all of them are empty, it cannot determine the locale. My guess for what's happening is this: When Bash resets all local variables set up in _comp_expand_glob at the end of the function call, LC_COLLATE is first reset to an empty value before LC_ALL= is reset, which causes a temporary state where all LANG, LC_COLLATE, and LANG are empty.

[akinomyoga]

Hmm, even if all variables LANG, LC_COLLATE, and LANG are empty, POSIX requires the system to use the implementation-defined default locale: "Otherwise, the implementation-defined default locale shall be used.".

I have a question. What happens with the following command in your system?

$ (LANG= LC_COLLATE= LC_ALL= locale)

[RainmanVi]

My result is:

$ (LANG= LC_COLLATE= LC_ALL= locale)
LANG=""
LC_COLLATE="C"
LC_CTYPE="UTF-8"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL="C/UTF-8/C/C/C/C"

This is unusual.

Yes, a long time ago I noticed that even if the LC_ALL is set via export LC_ALL="en_US.UTF-8" in my .bashrc, the macOS's default Terminal app won't set LANG. The different behavior can be observed with VS Code's built-in terminal:

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

I guess the reason is that when started by the Terminal app, the execution order of the start-up files is:

/etc/profile -> /etc/bashrc -> /etc/bashrc_Apple_Terminal -> ~/.bash_profile -> ~/.bashrc

The key difference between VS Code's terminal and macOS's Terminal is whether /etc/bashrc_Apple_Terminal is executed or not. But I cannot understand what happened.

$ cat /etc/profile                  
# System-wide .profile for sh(1)

if [ -x /usr/libexec/path_helper ]; then
	eval `/usr/libexec/path_helper -s`
fi

if [ "${BASH-no}" != "no" ]; then
	[ -r /etc/bashrc ] && . /etc/bashrc
fi

$ cat /etc/bashrc 
# System-wide .bashrc file for interactive bash(1) shells.
if [ -z "$PS1" ]; then
   return
fi

PS1='\h:\W \u\$ '
# Make bash check its window size after a process completes
shopt -s checkwinsize

[ -r "/etc/bashrc_$TERM_PROGRAM" ] && . "/etc/bashrc_$TERM_PROGRAM"

$ cat /etc/bashrc_Apple_Terminal 
# bash support for Terminal.


# Working Directory
#
# Tell the terminal about the current working directory at each prompt.

if [ -z "$INSIDE_EMACS" ]; then
    update_terminal_cwd() {
	# Identify the directory using a "file:" scheme URL, including
	# the host name to disambiguate local vs. remote paths.
	
	# Percent-encode the pathname.
	local url_path=''
	{
	    # Use LC_CTYPE=C to process text byte-by-byte and
	    # LC_COLLATE=C to compare byte-for-byte. Ensure that
	    # LC_ALL and LANG are not set so they don't interfere.
	    local i ch hexch LC_CTYPE=C LC_COLLATE=C LC_ALL= LANG=
	    for ((i = 0; i < ${#PWD}; ++i)); do
		ch="${PWD:i:1}"
		if [[ "$ch" =~ [/._~A-Za-z0-9-] ]]; then
		    url_path+="$ch"
		else
		    printf -v hexch "%02X" "'$ch"
		    # printf treats values greater than 127 as
		    # negative and pads with "FF", so truncate.
		    url_path+="%${hexch: -2:2}"
		fi
	    done
	}
	
	printf '\e]7;%s\a' "file://$HOSTNAME$url_path"
    }
    PROMPT_COMMAND="update_terminal_cwd${PROMPT_COMMAND:+; $PROMPT_COMMAND}"
fi


# Resume Support: Save/Restore Shell State
#
# Terminal assigns each terminal session a unique identifier and
# communicates it via the TERM_SESSION_ID environment variable so that
# programs running in a terminal can save/restore application-specific
# state when quitting and restarting Terminal with Resume enabled.
#
# The following code defines a shell save/restore mechanism. Users can
# add custom state by defining a shell_session_save_user_state function
# that writes restoration commands to the session file at exit. e.g.,
# to save a variable:
#
#   shell_session_save_user_state() { echo MY_VAR="'$MY_VAR'" >> "$SHELL_SESSION_FILE"; }
#
# During shell startup the session file is executed. Old files are
# periodically deleted.
#
# The default behavior arranges to save and restore the bash command
# history independently for each restored terminal session. It also
# merges commands into the global history for new sessions. Because
# of this it is recommended that you set HISTSIZE and HISTFILESIZE to
# larger values.
#
# You may disable this behavior and share a single history by setting
# SHELL_SESSION_HISTORY to 0. There are some common user customizations
# that arrange to share new commands among running shells by
# manipulating the history at each prompt, and they typically include
# 'shopt -s histappend'; therefore, if the histappend shell option is
# enabled, per-session history is disabled by default. You may
# explicitly enable it by setting SHELL_SESSION_HISTORY to 1.
#
# The implementation of per-session command histories in combination
# with a shared global command history is incompatible with the
# HISTTIMEFORMAT variable--the timestamps are applied inconsistently
# to different parts of the history; therefore, if HISTTIMEFORMAT is
# defined, per-session history is disabled by default.
#
# Note that this uses PROMPT_COMMAND to enable per-session history
# the first time for each new session. If you customize PROMPT_COMMAND
# be sure to include the previous value. e.g.,
#
#   PROMPT_COMMAND="${PROMPT_COMMAND:+$PROMPT_COMMAND; }your_code_here"
#
# Otherwise, the per-session history won't take effect until the first
# restore.
#
# The save/restore mechanism is disabled if the following file exists:
#
#   ~/.bash_sessions_disable

if [ ${SHELL_SESSION_DID_INIT:-0} -eq 0 ] && [ -n "$TERM_SESSION_ID" ] && [ ! -e "$HOME/.bash_sessions_disable" ]; then
    
    # Do not perform this setup more than once (which shouldn't occur
    # unless the user's ~/.bash_profile executes /etc/profile, which
    # is normally redundant).
    SHELL_SESSION_DID_INIT=1
    
    # Set up the session directory/file.
    SHELL_SESSION_DIR="$HOME/.bash_sessions"
    SHELL_SESSION_FILE="$SHELL_SESSION_DIR/$TERM_SESSION_ID.session"
    mkdir -m 700 -p "$SHELL_SESSION_DIR"
    
    #
    # Restore previous session state.
    #
    
    if [ -r "$SHELL_SESSION_FILE" ]; then
	. "$SHELL_SESSION_FILE"
	rm "$SHELL_SESSION_FILE"
    fi
    
    #
    # Note: Use absolute paths to invoke commands in the exit code and
    # anything else that runs after user startup files, because the
    # search path may have been modified.
    #
    
    #
    # Arrange for per-session shell command history.
    #
    
    shell_session_history_allowed() {
	# Return whether per-session history should be enabled.
	if [ -n "$HISTFILE" ]; then
	    # If this defaults to off, leave it unset so that we can
	    # check again later. If it defaults to on, make it stick.
	    local allowed=0
	    if shopt -q histappend || [ -n "$HISTTIMEFORMAT" ]; then
		allowed=${SHELL_SESSION_HISTORY:-0}
	    else
		allowed=${SHELL_SESSION_HISTORY:=1}
	    fi
	    if [ $allowed -eq 1 ]; then
		return 0
	    fi
	fi
	return 1
    }
    
    if [ ${SHELL_SESSION_HISTORY:-1} -eq 1 ]; then
	SHELL_SESSION_HISTFILE="$SHELL_SESSION_DIR/$TERM_SESSION_ID.history"
	SHELL_SESSION_HISTFILE_NEW="$SHELL_SESSION_DIR/$TERM_SESSION_ID.historynew"
	SHELL_SESSION_HISTFILE_SHARED="$HISTFILE"
	
	shell_session_history_enable() {
	    (umask 077; /usr/bin/touch "$SHELL_SESSION_HISTFILE_NEW")
	    HISTFILE="$SHELL_SESSION_HISTFILE_NEW"
	    SHELL_SESSION_HISTORY=1
	}
	
	# If the session history already exists and isn't empty, start
	# using it now; otherwise, we'll use the shared history until
	# we've determined whether users have enabled/disabled this.
	if [ -s "$SHELL_SESSION_HISTFILE" ]; then
	    history -r "$SHELL_SESSION_HISTFILE"
	    shell_session_history_enable
	else
	    # At the first prompt, check whether per-session history should
	    # be enabled. Delaying until after user scripts have run allows
	    # users to opt in or out. If this doesn't get executed (because
	    # the user has replaced PROMPT_COMMAND instead of concatenating
	    # it), we'll check at shell exit; that works, but doesn't start
	    # the per-session history until the first restore.
	    
	    shell_session_history_check() {
		if [ ${SHELL_SESSION_DID_HISTORY_CHECK:-0} -eq 0 ]; then
		    SHELL_SESSION_DID_HISTORY_CHECK=1
		    if shell_session_history_allowed; then
			shell_session_history_enable
		    fi
		    # Remove this check if we can; otherwise, we rely on the
		    # variable above to prevent checking more than once.
		    if [ "$PROMPT_COMMAND" = "shell_session_history_check" ]; then
			unset PROMPT_COMMAND
		    elif [[ $PROMPT_COMMAND =~ (.*)(; *shell_session_history_check *| *shell_session_history_check *; *)(.*) ]]; then
			PROMPT_COMMAND="${BASH_REMATCH[1]}${BASH_REMATCH[3]}"
		    fi
		fi
	    }
	    PROMPT_COMMAND="shell_session_history_check${PROMPT_COMMAND:+; $PROMPT_COMMAND}"
	fi
	
	shell_session_save_history() {
	    # Save new history to an intermediate file so we can copy it.
	    shell_session_history_enable
	    history -a
	    # If the session history doesn't exist yet, copy the shared history.
	    if [ -f "$SHELL_SESSION_HISTFILE_SHARED" ] && [ ! -s "$SHELL_SESSION_HISTFILE" ]; then
		echo -ne '\n...copying shared history...' >&2
		(umask 077; /bin/cp "$SHELL_SESSION_HISTFILE_SHARED" "$SHELL_SESSION_HISTFILE")
	    fi
	    # Save new history to the per-session and shared files.
	    echo -ne '\n...saving history...' >&2
	    (umask 077; /bin/cat "$SHELL_SESSION_HISTFILE_NEW" >> "$SHELL_SESSION_HISTFILE_SHARED")
	    (umask 077; /bin/cat "$SHELL_SESSION_HISTFILE_NEW" >> "$SHELL_SESSION_HISTFILE")
	    : >| "$SHELL_SESSION_HISTFILE_NEW"
	    # If there is a history file size limit, apply it to the files.
	    if [ -n "$HISTFILESIZE" ]; then
		echo -n 'truncating history files...' >&2
		HISTFILE="$SHELL_SESSION_HISTFILE_SHARED"
		HISTFILESIZE="$HISTFILESIZE"
		HISTFILE="$SHELL_SESSION_HISTFILE"
		HISTFILESIZE="$size"
		HISTFILE="$SHELL_SESSION_HISTFILE_NEW"
	    fi
	    echo -ne '\n...' >&2
	}
    fi
    
    #
    # Arrange to save session state when exiting the shell.
    #
    
    shell_session_save() {
	# Save the current state.
	if [ -n "$SHELL_SESSION_FILE" ]; then
	    echo -ne '\nSaving session...' >&2
	    (umask 077; echo 'echo Restored session: "$(/bin/date -r '$(/bin/date +%s)')"' >| "$SHELL_SESSION_FILE")
	    declare -F shell_session_save_user_state >/dev/null && shell_session_save_user_state
	    shell_session_history_allowed && shell_session_save_history
	    echo 'completed.' >&2
	fi
    }
    
    # Delete old session files. (Not more than once a day.)
    SHELL_SESSION_TIMESTAMP_FILE="$SHELL_SESSION_DIR/_expiration_check_timestamp"
    shell_session_delete_expired() {
	if ([ ! -e "$SHELL_SESSION_TIMESTAMP_FILE" ] || [ -z "$(/usr/bin/find "$SHELL_SESSION_TIMESTAMP_FILE" -mtime -1d)" ]); then
	    local expiration_lock_file="$SHELL_SESSION_DIR/_expiration_lockfile"
	    if /usr/bin/shlock -f "$expiration_lock_file" -p $$; then
		echo -n 'Deleting expired sessions...' >&2
		local delete_count=$(/usr/bin/find "$SHELL_SESSION_DIR" -type f -mtime +2w -print -delete | /usr/bin/wc -l)
		[ "$delete_count" -gt 0 ] && echo $delete_count' completed.' >&2 || echo 'none found.' >&2
		(umask 077; /usr/bin/touch "$SHELL_SESSION_TIMESTAMP_FILE")
		/bin/rm "$expiration_lock_file"
	    fi
	fi
    }
    
    # Update saved session state when exiting.
    shell_session_update() {
	shell_session_save && shell_session_delete_expired
    }
    trap shell_session_update EXIT
fi

[akinomyoga]

Thanks for the interesting results.

How about this? Does this produce an error message?

$ (LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0)

even if the LC_ALL is set via export LC_ALL="en_US.UTF-8" in my .bashrc, the macOS's default Terminal app won't set LANG.

That's expected. Setting the environment variable LC_ALL shouldn't affect the environment variable LANG. If you want LANG to be initialized, you need to set LANG instead of LC_ALL. You need to put export LANG=en_US.UTF-8 in .bashrc or .bash_profile.

The key difference between VS Code's terminal and macOS's Terminal is whether /etc/bashrc_Apple_Terminal is executed or not. But I cannot understand what happened.

Apart from the files that are sourced by Bash, a terminal can set environment variables that the Bash inherits. VS Code may set the LANG environment variable before performing exec to Bash.

[RainmanVi]

Thank you for your explanation. That makes sense to me.

My result is:

$ (LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0)
Segmentation fault: 11     ( LANG= LC_COLLATE= LC_ALL=; printf '%f\n' 1.0 )

Yes, it is a segmentation fault. What does this indicate?

[akinomyoga]

Yes, it is a segmentation fault. What does this indicate?

There aren't any problems with the above command in Bash on GNU/Linux and Cygwin (in my environment at least). This means that Bash or macOS has a bug in this area.

[akinomyoga]

@scop @yedayak Do you have macOS? If so, does this segmentation fault reproduce in your macOS?

$ (LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0)
Segmentation fault: 11     ( LANG= LC_COLLATE= LC_ALL=; printf '%f\n' 1.0 )

[akinomyoga]

I don't have macOS so cannot reproduce the problem, but someone who can reproduce the problem may further investigate this using gdb, lldb, or valgrind.

$ gdb bash
(gdb) r -c "LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0"
(gdb) bt
$ valgrind bash -c "LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0"

[yedayak]

@scop @yedayak Do you have macOS? If so, does this segmentation fault reproduce in your macOS?

$ (LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0)
Segmentation fault: 11 ( LANG= LC_COLLATE= LC_ALL=; printf '%f\n' 1.0 )

No macOS :(
Ran it in CI here: https://github.com/scop/bash-completion/actions/runs/17884851943/job/50857209373?pr=1339
Didn't seem to crash

The commit I added to #1339 for the test:

diff --git a/test/macos-script.sh b/test/macos-script.sh
index 6cc067e4..747146d7 100755
--- a/test/macos-script.sh
+++ b/test/macos-script.sh
@@ -1,5 +1,9 @@
 #!/bin/sh -eux

+set -x
+(LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0)
+exit
+
 # Note that this script is intended to be run only in throwaway environments;
 # it may install undesirable things to system locations (if it succeeds in
 # that).

[akinomyoga]

Thanks, so it could be an issue of Bash 5.3 (as macos-script.sh is executed by /bin/sh which is Bash 3.2.57), an issue of macOS 14 (as macos-latest seems to be macOS 15), or an issue in the reporter's environment.

[RainmanVi]

After some more trials and errors, I think it's a bug of the Homebrew version of Bash 5.3 (GNU bash, version 5.3.3(1)-release (aarch64-apple-darwin23.6.0)):

% /bin/bash -c "(LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0)"
1.000000

% /opt/homebrew/bin/bash -c "(LANG= LC_COLLATE= LC_ALL= ; printf '%f\n' 1.0)" 
/opt/homebrew/bin/bash: line 1: 18004 Segmentation fault: 11     ( LANG= LC_COLLATE= LC_ALL=; printf '%f\n' 1.0 )

Thanks a lot for your advice and help!