使用Cask和Emacs.app

Question

Cask uses the built-in emacs on OSX which does not support the --script argument which Cask requires. Is there some way to tell Cask to use the Emacs.app version?

I tried the solutions here: How to start "emacsformacosx" in terminal but they did not help.

I finally just entered the command supplied at the bottom of the cask file:

/Applications/Emacs.app/Contents/MacOS/Emacs -Q --script ~/.cask/cask-cli.el

This is not very elegant.

Answer 1

You can tell cask which Emacs executable to run, by exporting the environment variable $EMACS :

$ export EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs
$ cask install

To avoid the repetitive process of setting this variable any time you want to use cask , you need to create a command line wrapper for Emacs.app. It must be a proper executable on its own, and not merely a shell alias or function such as recommended at How to start "emacsformacosx" in terminal , because neither aliases nor shell functions are available for subprocesses of a shell.

This is easily done by creating a file /usr/local/bin/emacs , with the following contents

#!/bin/bash
exec /Applications/Emacs.app/Contents/MacOS/Emacs -nw "$@"

You will need root privileges to create this file, and you must mark it as executable afterwards:

$ sudo chmod a+x /usr/local/bin/emacs

After this, you should be able to start Emacs.app from command line with emacs . This is sufficient for Cask to pick up Emacs.app without setting $EMACS .

Alternatively, you may want to install Emacs with Homebrew, by

$ brew install emacs --cocoa --srgb --with-gnutls
$ brew linkapps

This automatically creates the command line wrapper, and has some other advantages, such as building with some additional libraries.

I strongly recommend the Homebrew approach.