How to run racket with geiser: getting error:Can't exec program: /Applications/Racketv6.0/DrRacket.app

Question

I am new to Emacs and I am having a bit of trouble. I am looking to run racket from Emacs using Geiser. I told Emacs where racket is as follows:

(setq geiser-racket-binary "/Applications/Racket\ v6.0/DrRacket.app")

(I took this from StackOverflow question: Setting Racket Geiser Emacs Path.)

I start by compiling the racket code that is saved. However, when I attempt to hit M-x followed by run-geiser, it then prompts me for a Scheme implementation. At this point I type racket. Emacs now opens a racket REPL buffer and in that buffer it leaves the error:

Can't exec program: /Applications/Racketv6.0/DrRacket.app .

If it helps, here is my .emacs file:

(custom-set-variables
 ;; custom-set-variables was added by Custom.
 ;; If you edit it by hand, you could mess it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.

 '(geiser-repl-startup-time 20000)
 '(package-archives (quote (("gnu" . "elpa gnu packages website") ("melpa" . "http://melpa.milkbox.net/#/"))))    
 '(package-directory-list (quote ("/Applications/Emacs.app/Contents/Resources/site-lisp/elpa")))    
 '(python-python-command "/usr/local/bin/python3"))

(setq geiser-racket-binary "/Applications/Racket\ v6.0/DrRacket.app")    
(setq-default cursor-type 'bar)

(custom-set-faces
 ;; custom-set-faces was added by Custom.
 ;; If you edit it by hand, you could mess it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 '(default ((t (:inherit nil :stipple nil :background "controlDarkShadowColor" :foreground "Green" :inverse-video nil :box nil :strike-through nil :overline nil :underline nil :slant normal :weight normal :height 120 :width normal :foundry "apple" :family "Monaco")))))

(require 'package)

(add-to-list 'package-archives 
     '("marmalade" .
      "http://marmalade-repo.org/packages/"))
(package-initialize)

Answer 1

I think you are referencing the wrong executable.

"DrRacket" is an IDE (with a graphical user interface) for editing Racket code. From man drracket:

DrRacket is the Racket programming environment.

Try setting geiser-racket-binary to the location of the racket executable (which is the "core Racket implementation") instead.

---

EDIT

If the naming scheme of the Mac installation of Racket is anything like the one used for the Linux installation, there should be a binary called Racket or racket in a location similar to where you can find the DrRacket (or drracket) binary:

$ locate racket
...
/usr/bin/drracket
/usr/bin/gracket
/usr/bin/gracket-text
/usr/bin/racket
...

(Not suggesting that you will find the binaries in /usr/bin/, just trying to illustrate that there is a good chance all binaries that are possibly relevant are located in the same directory.)

Answer 2

On OS X xxx.app is technically a directory. The actual executable file is located in Content/MacOS/xxx (if my memory serves me correctly).

EDIT: In other words, you should write something like:

(setq geiser-racket-binary "/Applications/Racket\ v6.0/DrRacket.app/Content/MacOS/DrRacket")

Note: I'n not at my Mac so I can't verify the details right now.