Pipenv: "command not found" when pipenv shell, .bashrc is empty

[SHxKM]

OS: macOS

As I understand from reading on SO and some issues here, pipenv launches non-login shells, which means it should ignore .bash_profile, and only use .bashrc:

"Because Pipenv only reads bashrc and that’s it. Use the above workarounds." - @uranusjr in #844

My .bashrc is empty.

I've been moving around stuff in my dotfiles just to get pipenv to work properly but I'm not having too much success. This is the error I see when pipenv shell is run in a project directory:

bash: prompt_git: command not found

prompt_git is a function defined in .bash_prompt, which is sourced in .bash_profile. So why is pipenv still complaining?

In .bash_profile, which pipenv seems to be using, I've also tried doing conditionally sourcing this .bash_prompt just to satisfy pipenv:

if shopt -q login_shell; then

    if [[ $- == *i* ]]; then
        if [ -f ~/.bash_prompt ]; then
            source ~/.bash_prompt
        fi
    fi 
fi

But that isn't helping either.

[uranusjr]

I assume you use prompt_git in your prompt? The $PROMPT_COMMAND environment variable is executed for every prompt display, so the error is raised exactly because you don’t have the command defined.

[SHxKM]

So does pipenv read .bash_profile, after all?

Where and how should I define this env var so pipenv works?

[uranusjr]

No, the $PROMPT_COMMAND environment variable was inherited from the parent shell. The general recommendation is to make .bash_prompt available in both .bashrc and .bash_profile.

[SHxKM]

The general recommendation is to make .bash_prompt available in both .bashrc and .bash_profile.

Ok, this worked, thank you.

But I'm still a little confused, let me see if I understand: pipenv's subshell inherited the $PROMPT_COMMAND env var from its interactive login parent shell, and that variable had a reference for something that was only in .bash_profile, but since pipenv itself doesn't source that file, then basically $PROMPT_COMMAND was referencing an undefined command?

[uranusjr]

Yeah I know, it’s very confusing, that’s how Bash works. A child process inherits the parent’s environment (unless explicitly set otherwise), so all environment variables are automatically available in a sub-shell without configuration. Bash functions, however, are not part of the environment, and are therefore not inherited.

Bash internally (as I understand it) stores $PROMPT_COMMAND as a string, and eval it for every prompt. It does not carry the referenced function with it when copied into the child shell (only the name, as a string), so the child shell gets a reference error when trying to eval it.

I read here that it is also possible to use export -f to make functions available in a child shell. I am not sure whether that works with pipenv shell, however.

[SHxKM]

Awesome, thanks for the explanation.