brew installed vim --with-python3

[kenhan]

I have python3 installed via homebrew. When I 'brew install vim --with-python3' vim installs successfully, and 'vim --version' shows ' +python3/dyn '

But when I open vim and do

:py3 print("hello")

it returns
E370: Could not load library Python.framework/Versioins/3.3/Python
E263: Sorry, this command is disabled, they Python library could not be loaded.

Can someone explain why vim --version shows +python3/dyn but it actually does not work? Thanks!

[samueljohn]

I am going to investigate this. I know I built vim with python3 earlier and was able to print.

[mbcoguno]

Vim will drop all python linking flags while you build with enable both python2 and python3 binding. That is vim will not load homebrew's framework if you build vim this way.

[kenhan]

@samueljohn Thanks for looking into it. Anything yet?
@mbcoguno Also, thanks. But when I brew install vim --with-python3 without --with-python it builds successfully, but vim --version shows +python/dyn AND +python3/dyn. Then :py3 print("hello") from inside vim still gives me the same error as before.

[kenhan]

I had to explicitly pass --without-python while building vim: so
brew install vim --with-python3 --without-python built vim with python3 support, and :py3 print("hello") now works as expected.

[mistydemeo]

@samueljohn Is this expected?

[samueljohn]

not solved yet. Reopening.

I assumed brew install vim --with-python3 installs for both python 2.x and 3.x. But note when you first issue an :python command inside vim (and perhaps from the .vimrc), vim will disable :python3 and vice versa. So The first command decides if you are running python 2.x or 3.x. At least that is what I got from testing.

But I have not completely looked into this.

[samueljohn]

For MacVim, I had to remove Python 3.x support because it caused the MacVim window to disappear and the 2.x Python was also not working.

But since ee0d6c0, python 2.x from homebrew should work with MacVim. I'll look into the vim issue here, next

[samueljohn]

I label this upstream-issue. I don't know how to fix ...

[kenhan]

Thanks for looking into it. In the mean time, can you revert it back to the way it use to be? I can't build vim with python3 enabled anymore no matter what argument I pass to brew install vim

[samueljohn]

@kenhan I had to disable python 3.x support until someone is able to find a fix (perhaps upstream) because it breaks 2.x bindings and most people still use 2.x.

I'd love to have both bindings but MacVim seems to get confused.

[kenhan]

@samueljohn I see. Thanks again!

[samueljohn]

As a side-node: Brew does not complain if you pass options to brew install that are not available. This is hard to fix because you can see this as a feature because options are passed down to deps, so if some formula has --with-python, the deps are also automatically installed with this option.

[kenhan]

Has there been any progress here? Still would like to have python3 support in vim.

[adamv]

There have been recent fixes to superenv/stdenv, as well as updates to Python and Vim in the last two months.

Can someone brew update and try this fresh?

[kenhan]

Still no success building with python3 support. brew install vim --with-perl --with-ruby --with-python3 builds vim successfully with perl and ruby, but not python3, although it shows +python

Similarly, brew install vim --with-perl --with-ruby builds vim with +python.

[samueljohn]

@kenhan and if you disable Python 2.x by passing --without-python --with-python3 ? I guess building vim with both at the same time might be even trickier... (I have not tried)

[samueljohn]

Can someone explain why vim --version shows +python3/dyn but it actually does not work? Thanks!

Vim's build system is strange. It detects python correctly but then fails to link because it does not use the recommended standard method of python-config --ldflags to figure out the linking parameter.

[samueljohn]

Oh btw. we don't have an option --with-python3 for vim! So no surprise here. But pull requests that add depends_on :python3 and get vim's build system to use a brewed python3 are welcome.

[mbcoguno]

#21366.
This is WIP. I can drop external frameworked Python now.

BTW, python[3]/dyn will loaded Python only from OSX defined location, like /Library/Frameworks.

[samueljohn]

Can we patch (or inreplace) such that it used the actual python framework location and not the hard coded one?
In homebrew python.framework might help to get the dir.

[mbcoguno]

@samueljohn Updated #21366 is done. Now vim can load brewed Python dynamic library using absolute path.

[samueljohn]

@mbcoguno cool ... I'll check your PR. That is good news!