Suppressing "The default interactive shell is now zsh" message in macOS Catalina

Question

I know Catalina uses zsh as the default login shell and interactive shell, but it is very annoying when I open iTerm.app or run command with /bin/bash, it shows verbose message like below:

$ /bin/bash
The default interactive shell is now zsh.
To update your account to use zsh, please run `chsh -s /bin/zsh`.
For more details, please visit https://support.apple.com/kb/HT208050.

The support document the message links to is https://support.apple.com/kb/HT208050

How can I hide the verbose logging? I do not want to be reminding that the "default interactive shell is now zsh" every time I open Terminal.

Answer 1

I found the solution on reddit. The solution is also mentioned in the "How to use a different shell without changing the default" section of the Apple support article mentioned in the bash warning: https://support.apple.com/en-us/HT208050/.

Add:

export BASH_SILENCE_DEPRECATION_WARNING=1

to $HOME/.bash_profile, $HOME/.profile or $HOME/.bashrc and restart iTerm. After that, the warning message will be gone.

Answer 2

Apple's /bin/bash is fairly antiquated (currently v3.2.57). I just switch to use the bash shipped by homebrew (currently v5.0.18), which will incidentally also remove that deprecation warning.

Steps:

1. Install Homebrew if you haven't already.
2. Install the latest bash shell with Homebrew:

brew update && brew install bash

3. If you have an Apple Intel computer, change the shell like this:

sudo chsh -s /usr/local/bin/bash $(whoami)

Or if you have Apple Silicon (e.g. M1):

sudo chsh -s /opt/homebrew/bin/bash $(whoami)

Answer 3

I found that becoming root, then adding the deprecation suppression in /etc/profile was more reliable. I was already using ZSH and I was getting the warning every time I opened a new console. Terribly annoying. /etc/profile now reads as follows:

    # System-wide .profile for sh(1)
    export BASH_SILENCE_DEPRECATION_WARNING=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

Answer 4

I did a bit of digging and found the extra text (I did read the URL given in the message but missed the line for export BASH_SILENCE_DEPRECATION_WARNING=1)

The issue is that the text you see comes from Apple's version of /bin/bash

strings /bin/bash | grep default shows the text.

So to use bash I would add a newer bash from another source and use that in chsh. I would use a different bash anyway as the Apple version is over 10 years old

Looking at Apple's code for macOS 11.3 in shell.c (Apple don't seem to have released it for 11.4 yet)

Apple have added amoungst other additions

#ifdef __APPLE__
  if (interactive_shell && !act_like_sh) {
      char const * const silence_warning = getenv("BASH_SILENCE_DEPRECATION_WARNING");
      if (!silence_warning || *silence_warning != '1') {
          struct stat sbuf;
          if (stat("/bin/zsh", &sbuf) == 0) {
              fprintf(stderr, "\n"
                              "The default interactive shell is now zsh.\n"
                              "To update your account to use zsh, please run `chsh -s /bin/zsh`.\n"
                              "For more details, please visit https://support.apple.com/kb/HT208050.\n");
          }
      }
  }
#endif

So setting BASH_SILENCE_DEPRECATION_WARNING will remove this (but see the comment on bash being an old version so I would not advise this)

Answer 5

If you are using (as the biggest part of us) iTerm as a teminal emulator and since the bash shipped with osx is rather old the best solution (IMHO) is to configure iTerm to use brew bash and leave the default system shell to whatever else configured by the system (unless you have a reason to do otherwise).

The pros are that, if accidentally brew get removed, the shell stuff related to your account will continue to work.

The cons are that script executed at boot or at login still use the original (old) bash. This can be a problem or a "feature". Surely those who have these types of problems also know how to solve them.

To do so the steps are:

• install brew
• install bash using brew
• configure iTerm to execute brew bash when you open a new window (or tab)

The defaul shell for iTerm can be configured on profiles. For example to change shell for Default profile:

• Open Preferences (menu iTerm -> Preferences)
• Select the pane with Profile configurations
• Select the desired profile
• Select "General" tab
• Under "Command" select "Custom Shell" from pop-up
• Type the path to your shell (/usr/local/bin/bash or /opt/homebrew/bin/bash)