__git_ps1 not found but does exist

Question

~/.bash_aliases where I set PS1, and is included in ~/.bashrc (the default settings)

# color PS1
PS1="\[\033[01;90m\]\D{%H:%M} \[\033[01;33m\]Ubuntu\[\033[00m\] \[\033[01;34m\]\w\[\033[01;35m\]$(__git_ps1) \[\033[01;36m\]\$\[\033[00m\] "

But when I start a terminal I get error __git_ps1: command not found

But when I run the function manual $ __git_ps1 in a git folder it does echo the current branch.

Also when I manually run
$ PS1="\[\033[01;90m\]\D{%H:%M} \[\033[01;33m\]Ubuntu\[\033[00m\] \[\033[01;34m\]\w\[\033[01;35m\]$(__git_ps1) \[\033[01;36m\]\$\[\033[00m\] "

the PS1 gets updated and __git_ps1 part does get added.

I did not install it myself. I only installed git.
sudo apt install -y git (git version 2.19.1)

__git_ps1 is defined in /usr/lib/git-core/git-sh-prompt (the file on github)

grep __git_ps1 ~/.bashrc ~/.profile ~/.bash_profile ~/bash.login ~/.bash_aliases /etc/bash.bashrc /etc/profile /etc/profile.d/* /etc/environment 2>/dev/null

Only the .bash_aliases file shows up.
A full grep of git-sh-promt only returns binary matches

sudo grep 'git-sh-prompt' -nr /

What is wrong here?

Solution

Using a de-colorized version for clarity:

PS1="\D{%H:%M} Ubuntu \w$(__git_ps1) \$ "

The double quotes tell Bash to evaluate what is between the quotes, including $(__git_ps1), but /usr/lib/git-core/git-sh-prompt hasn't been sourced yet, hence the error.

Simply change it to use single quotes, which will prevent $(__git_ps1) from being evaluated until the PS1 is evaluated (i.e. when the interactive shell is ready for input and shows you the prompt).

PS1='\D{%H:%M} Ubuntu \w$(__git_ps1) \$ '

Escaping the dollar sign also works, but it's harder to read:

PS1="\D{%H:%M} Ubuntu \w\$(__git_ps1) \$ "

By the way, ~/.bash_aliases is intended for shell aliases, so it's a weird place to put your PS1. Personally I would put it in ~/.bashrc instead.

Comments

[muru]

Please don't post screenshots of text. Copy the text here and apply code formatting instead.

[muru]

Also, if you used double quotes, $(__git_ps1) will be evaluated when PS1 is set, not when PS1 is used (i.e., when the prompt is printed).

[janw]

@muru I've added a more compact screenshot. I think it does my my problem more clear. The $() does work on other server where I've set the same ps1.

[muru]

The point is that we don't want screenshots when normal text will do. meta.askubuntu.com/q/8713/158442

[terdon]

Please edit your question and show us i) where the __git_ps1 function is defined. Is it even a function or is it a script? Where is it? ii) clarify where you set what. Is your PS1 being set in .bash_aliases? Is your .bash_aliases sourced by .bashrc (the default in Ubuntu, but perhaps you've changed something)? iii) Also show us the output of type __git_ps1

[janw]

@terdon I have updated my question. I can't find the definition, it's just part of git

[terdon]

No, it isn't part of git. You must be defining it somewhere. It may have been installed automatically for you, but it still needs to be sourced somewhere. Please edit your question and add the output of grep __git_ps1 ~/.bashrc ~/.profile ~/.bash_profile ~/bash.login ~/.bash_aliases /etc/bash.bashrc /etc/profile /etc/profile.d/* /etc/environment 2>/dev/null.

[PerlDuck]

Yes, @terdon, __git_ps1 does come with git, in particular with the file /usr/lib/git-core/git-sh-prompt. See my answer to the related question script to show git branch in bash no longer works on ubuntu 18.04.

[terdon]

@PerlDuck oh, I guess Ubuntu have bundled it with git. I meant it isn't part of git itself, although as you say it seems to be part of the git package in Ubuntu. Thanks.

[janw]

I have the git-sh-prompt. The function is inside. But I can't find a reference for it.

[PerlDuck]

You get that command not found only once, right? Not for every single prompt in the terminal? I'd guess the usage of __git_ps1 in the definition of $PS1 comes before the function gets defined (e.g. by sourcing git-sh-prompt or your file ~/.local/git-completion.bash (shown in an older version of your post)).

[janw]

Yes it's only once, Then it will set my PS1 to a var that does not contain the __git_ps1. It's very weird because I've never had this problem before. But it works... Can you add this as a answer?

[wjandrea]

Different issue, same solution: Why is my function not re-evaluated in PS1?

[janw]

Is there a way to check this source order?

[wjandrea]

@janw for source order, the closest you could get is bash -x, which is pretty verbose, but come to think of it, this could also help diagnose the original problem, cause it will show every command it executes during startup