This was changed by @iandol in #5511. @iandol could you provide some help/thoughts here? Thanks!

Hm, I found on both my macOS machines (both 10.14.2) and my Ubuntu 18.04 machines running Linuxbrew that the original .../etc/bash_completion was not present (thus source failed) yet I had a .../etc/bash_completion.d/ folder with several completion files within. I read around and understood this is the default path. I raised this on discourse here: https://discourse.brew.sh/t/bash-completion-and-brew-instructions-for-setting-up-completions/3808 — and Sean seemed to also think it should be bash_completion.d/

I do not know under what circumstances the brew installs the completion files in .../etc/bash_completion and when it uses .../etc/bash_completion.d

Here is where my completions are automatically put on macOS 10.14.2:

 ❯ ls $(brew --prefix)/etc/bash_completion.d/
bat.bash                        git-prompt.sh
brew                            npm
brew-services                   pandoc
git-completion.bash             youtube-dl.bash-completion

edit: I normally use zsh and do not have deep knowledge of bash...

I think this may be the difference between the bash-completion formula being installed and Bash completion files being installed from individual formulae. CC @maxim-belkin who has also been talking completions lately. I don't use Bash (ZSH 4 lyfe) but want to help where I can.

Yes, there may be some confusion from bash-completion package vs auto installed completion files. https://docs.brew.sh/Shell-Completion is talking about the auto installed completion files, so I assume it is /bash_completion.d/ while the bash-completion package appears to use /bash_completion?

@iandol @samuela I think ideally the docs would handle either/both and also if neither/none is installed.

One should source only one file:

$(brew --prefix)/etc/profile.d/bash_completion.sh

This file checks that Bash has the right version and then sources the right bash_completion file. In case you have bash-completion formula installed, it will source

/usr/local/Cellar/bash-completion/1.3_3/etc/bash_completion

If you have bash-completion@2 installed, it will source

/usr/local/Cellar/bash-completion@2/2.8/share/bash-completion/bash_completion

This bash_completion file provides some Bash-specific completions and also loads all the right program-specific completions.

But why does @samuela not even have a bash_completion.d/ on his system, as the completions files include brew and brew-services so I would have imagined they'd be present on all homebrew installs whether bash-completion was installed or not?

As for the docs, I wonder if the else ... echo "run: brew install git bash-completion" should be removed — as it only talks about Homebrew’s completions which is IINM not related to the bash-completion project.

While we're here, why does it recommend to use: if type brew 2&>/dev/null; then — why not just look for the folder directly?

@maxim-belkin thanks for your knowledge. However I don't have that file:

 ❯ ll $(brew --prefix)/etc/profile.d/bash_completion.sh
ls: /usr/local/etc/profile.d/bash_completion.sh: No such file or directory

bash-completion and bash-completion@2 store program-specific programmable completions in different folders (this is what I have on my Mac):

$ brew list bash-completion
/usr/local/Cellar/bash-completion/1.3_3/etc/bash_completion.d/ (180 files)
/usr/local/Cellar/bash-completion/1.3_3/etc/profile.d/bash_completion.sh
/usr/local/Cellar/bash-completion/1.3_3/etc/bash_completion

$ brew list bash-completion@2
/usr/local/Cellar/bash-completion@2/2.8/etc/profile.d/bash_completion2.sh
/usr/local/Cellar/bash-completion@2/2.8/share/bash-completion/ (657 files)
/usr/local/Cellar/bash-completion@2/2.8/share/cmake/ (2 files)
/usr/local/Cellar/bash-completion@2/2.8/share/pkgconfig/bash-completion.pc

@iandol what does brew list bash-completion or brew list bash-completion@2 return to you?

I have neither of them installed on my macOS system; I only have the default auto-installed completion files.

Then you shouldn't be surprised that you don't have $(brew --prefix)/etc/profile.d/bash_completion.sh

@maxim-belkin Please note what I wrote above:

I think ideally the docs would handle either/both and also if neither/none is installed.

Would be good to have something that handles bash-completion being installed or just bash_completion files being installed by formulae.

Would be good to have something that handles bash-completion being installed or just bash_completion files being installed by formulae.

Currently, the situation is as follows:

1. $(brew --prefix)/etc/bash_completion.d/ is used by:
   - brew
   - completions installed by individual formulae
   - bash-completion formula
2. bash-completion@2 formula installs its completion files in #{share}/bash-completion/

Both bash-completion and bash-completion@2 formulae provide special scripts that safe-guard against sourcing their completions under wrong Bash version.

Our options

1. Change bash-completion@2 formula to install its completions in $(brew --prefix)/etc/bash_completion.d/ and instruct users to blindly source all files in that directory. In that case we don't care about those special scripts that bash-completion and bash-completion@2 formula provide.

2. Don't change installation locations anywhere but make sure users understand that programmable completions installed by bash-completion formula will be sourced automatically if they source all files in $(brew --prefix)/etc/bash_completion.d/

3. Change bash-completions formula to install its completions in a different folder. In this case users will have to

   • source all files in $(brew --prefix)/etc/bash_completion.d/ (Brew + individual formulae-provided bash completions)
   • source one more script provided by either of the bash-completion* formulae

But why does @samuela not even have a bash_completion.d/ on his system, as the completions files include brew and brew-services so I would have imagined they'd be present on all homebrew installs whether bash-completion was installed or not?

I do in fact have that directory on my system. I think bash was complaining because that directory has no file named "*".

Bash translates * to a literal symbol * only when the directory is completely empty (0 non-hidden files/directories).

Brew installs its own completions in $(brew --prefix)/etc/bash_completion.d/, so this directory must exist. There might be something wrong with your setup. A quick-and-dirty fix would be to manually add a symbolic link to brew completions in there:

cd $(brew --prefix)/etc/profile.d/
ln -s ../../Homebrew/completions/bash/brew

@maxim-belkin Could you suggest a version that will work for the docs even if none of these files or directories exist?

sure...

I've opened #5625 to improve these instructions. Let me know what you all think.

Great, thanks @maxim-belkin.

@MikeMcQuaid — if we think @samuela's empty folder is not a totally isolated incident, is it worth to also check the directory is not empty, something like [ -z "$(ls -A $(brew --prefix)/etc/bash_completion.d)" ] — or is this overkill for an isolated incident?

@iandol Can we move discussion to #5625, it's hard to keep track of both place.