Rails: Python2 error on yarn install

I recently worked on a legacy codebase that requires Python2, which has been deprecated for some time and is no longer available via homebrew.

Using this Stack Overflow thread I was able to resolve the issue as below. Note that the “pyenv global” command might interfere with with your Python3 environment.

The Error

➜ yarn install --check-files
gyp verb command configure []
gyp verb check python checking for Python executable "python2" in the PATH
gyp verb `which` failed Error: not found: python2

➜ which python
python not found

➜ which python2
python2 not found

The Fix

➜ brew install pyenv
➜ pyenv install 2.7.18
➜ pyenv global 2.7.18
➜ PATH=$(pyenv root)/shims:$PATH
➜ which python2
/Users/user/.pyenv/shims/python2

➜ yarn install --check-files
yarn install v1.22.19
...
Done in 10.26s

Add to ~/.bashrc or ~/.zshrc to make available in future shell sessions:

# make python exe available globally
PATH=$(pyenv root)/shims:$PATH

Rails: Error installing gem mysql2 on MacOs

When installing gems on a new project under MacOs using bundler, I encountered the following error for MySql:

Installing mysql2 0.5.2 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

linking shared-object mysql2/mysql2.bundle
ld: library not found for -lssl
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [mysql2.bundle] Error 1

It seems the clang compiler couldn’t find an SSL library on the system. The solution was:

> brew install openssl
> bundle config --global build.mysql2 --with-opt-dir="$(brew --prefix openssl)
> bundle

# This also works:
> export LIBRARY_PATH=$LIBRARY_PATH:/usr/local/opt/openssl/lib/

Remapping Caps Lock to Control and Escape in macOS Big Sur

For more better text editing and great success.

I’m a big fan of VIM modal editing and keeping keyboard shortcuts as close to the home row as possible. This philosophy allows fluid text editing and staying in the “programming flow state”.

Remapping the Caps Lock key to Control and Escape is a big part of this workflow. Pressing and releasing sends the Escape key, while pressing and holding emulates the Control Key.

In macOS, I’d been using Karabiner Elements to enable this remapping, however with macOS Big Sur I could no longer get the configuration to work. This was a serious annoyance, since the VIM shortcuts are burned into my fingertips.

Enter HammerSpoon! Using the ControlEscape plugin, I am now back in remapping bliss. Below are the System Preference settings required to make this setup work.

Troubleshooting

If you use multiple keyboards with your mac, for example an Apple Magic bluetooth keyboard, the modifier keys are configured individually for each one – so make sure the correct keyboard is chosen in the “Select keyboard” dropdown:

neovim: macos tmux and netrw/vinegar clipboard errors

So it looks like MacOS Sierra broke pbcopy/pbpaste for tmux. This manifests as clipboard errors when using netrw/vinegar in neovim under tmux. (Dunno why netrw is writing to the clipboard but anyways).

The solution is to use Homebrew to reinstall a patched version of reattach-to-user-namespace:

brew uninstall reattach-to-user-namespace
brew install reattach-to-user-namespace --with-wrap-pbcopy-and-pbpaste

Although this was annoying, it did lead to running brew cleanup which reclaimed 3.8GB of disk space. Jinkies!