Firebase Studio ターミナルのコマンド いつものやつの戻し方

Firebase Studio(旧Project IDX)のVS Codeで以下のようなインタラクティブシェルになってしまうとClineのようなターミナルを操作できるAIコーディングエージェントが止まってしまい困ってしまいます。

$ cowsay
cowsay is not installed, but available in the following packages, pick one to run it, Ctrl+C to cancel.
> 
cowsay
neo-cowsay

以下コマンドを実行することで解決できます。

$ unset -f command_not_found_handle

いつも通りのエラー表示になりました。

$ cowsay
bash: cowsay: command not found

どうやらbashの「command not found」をカスタムしているからサブシェルが起動してしまうようです。
実際にFirebase Studioの.bashrcを確認してみましょう。

$ cat ~/.bashrc
# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern "**" used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
#[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
    debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
    xterm-color|*-256color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
        # We have color support; assume it's compliant with Ecma-48
        # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
        # a case would tend to support setf rather than setaf.)
        color_prompt=yes
    else
        color_prompt=
    fi
fi

if [ "$color_prompt" = yes ]; then
    current_git_branch() {
        git branch 2>/dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/{\1}/'
    }
    PS1='\[\033[00;35m\]$WORKSPACE_SLUG\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\[\033[01;32m\]$(current_git_branch)\[\033[00m\]$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
    PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
    ;;
*)
    ;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
    alias ls='ls --color=auto'
    alias dir='dir --color=auto'
    alias vdir='vdir --color=auto'
    alias grep='grep --color=auto'
    alias fgrep='fgrep --color=auto'
    alias egrep='egrep --color=auto'
fi

# colored GCC warnings and errors
#export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'

# some more ls aliases
alias ll='ls -l'
alias la='ls -A'
alias l='ls -CF'

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
    . ~/.bash_aliases
fi

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if ! shopt -oq posix; then
  if [ -f /usr/share/bash-completion/bash_completion ]; then
    . /usr/share/bash-completion/bash_completion
  elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
  fi
fi

if [ ! -z "$CUSTOM_ENV_ENABLED" ]; then
  function command_not_found_handle {
    exec _idx_command_not_found "$@"
  }
fi

一番最後にありました。
.idx/dev.nixのenvでCUSTOM_ENV_ENABLEDを"false"にしたり、code ~/.bashrcで.bashrcを編集したりしてもうまくいかなかったため、bash起動後にcommand_not_found_handle関数の処理をなくしてしまうunset -f command_not_found_handleを使うのが一番手っ取り早いようです。