Homebrew Python – What Does ‘link: false’ Mean in Brewfile?

homebrewpython

My Brewfile created with brew bundle dump contains one line with link: false:

...
brew "git"
brew "python@3.8", link: false
brew "glib"
...

I don't see any kind of --link option for the brew install command, so I don't think it's a record of some install option for python@3.8. The only potentially relevant thing about it I see in either the brew and homebrew-bundle documentation is the brew link command, which I have not used.

And as far as I can tell, the python3.8 command is installed and works the same as any of the other packages listed in the Brewfile.

Best Answer

The link:false in the Brewfile appears to skip linking the installed binary in /usr/local/Cellar/... into /usr/local/bin (and thus my user $PATH) during bulk installation with brew bundle install.

I am guessing since python@3.8 was installed both as a dependency for something else (and thus not linked?) and it was also installed manually, it somehow erroneously was being output in the Brewfile as link: false though it should not have been.

Getting brew bundle dump to stop outputting the link: false was accomplished by forcibly uninstalling and reinstalling:

$ brew uninstall --ignore-dependencies python@3.8
$ brew install python@3.8
$ brew bundle dump

Related Solutions

How to prevent Homebrew from installing a duplicate of software I installed through other means

Take the path that you used for --prefix= during your ./configure and sym-link that into the Cellar/ directory that Homebrew is using. Homebrew will see these directories and see the dependencies as satisfied (unless you need to have them compiled with or without certain features to make Homebrew's formulas compile correctly). If your manually-compiled deps aren't compiled correctly, you'll probably get errors out of Homebrew.

ln -s /path/from/prefix/ /usr/local/Cellar/path/from/prefix

(Note the trailing slash on the first path, and lack of trailing slash on the second. OS X can be picky about these slashes when creating sym-links.)

This is the wrong way to do it, you should just be using --ignore-dependencies coq — that's what it's there for.

MacOS – Updating and running Git through Homebrew instead of XCode

This: ~/.bash_profile is a file, not a directory. It's a file that gets executed when you start a bash login shell:

A login shell is a bash shell that is started with - or --login.

When BASH is invoked as a login shell, the following files are executed in the displayed order.

/etc/profile

~/.bash_profile

~/.bash_login

~/.profile

To ensure your Homebrew-installed tools appear before any other tools you can copy and paste the following in to a terminal window to update your ~/.bash_profile file:

cat << 'EOF' >> ~/.bash_profile

export PATH="/usr/local/bin:$PATH"
EOF

This will append (>>) the necessary lines to ~/.bash_profile for you in a safe manner. The append will create the file if it does not exist. The heredoc syntax used above is explained in this nice StackOverflow answer.

After making changes to your .bash_profile file you need to reload it or start a new Terminal session to see the change. To reload it in your existing session type:

source ~/.bash_profile

Best Answer

Related Solutions

How to prevent Homebrew from installing a duplicate of software I installed through other means

MacOS – Updating and running Git through Homebrew instead of XCode

Related Question