Referencing #660 since it's closely related, didn't want to hijack the existing issue.

I have Emacs with stack-ghci and ghc-mod set up. I can't use ghc-mod, since it throws the error that seems to be well known and listed in the wiki:

ghc-mod: cabal: createProcess: runInteractiveProcess: exec: does not exist (No such file or directory)

However, there is a GHC executable on the path, both in what my shell has and what Emacs got from the environment.

Partial output from M-x ghc-debug:

Path: check if you are using intended programs.
      ghc.el path: /Users/chipf0rk/.emacs.d/elpa/ghc-20160108.701/ghc.el
     ghc-mod path: /Users/chipf0rk/.stack/snapshots/x86_64-osx/lts-5.13/7.10.3/bin/ghc-mod
         ghc path: /Users/chipf0rk/.stack/programs/x86_64-osx/ghc-7.10.3/bin/ghc

Version: all GHC versions must be the same.
      ghc.el version 5.5.0.0
     ghc-mod version 5.5.0.0 compiled by GHC 7.10.3
    The Glorious Glasgow Haskell Compilation System, version 7.10.3

Version of ghc-mod, and output of which ghc, both run from inside Emacs through M-x shell-command:

> ghc-mod --version
ghc-mod version 5.5.0.0 compiled by GHC 7.10.3

> which ghc
/Users/chipf0rk/.stack/programs/x86_64-osx/ghc-7.10.3/bin/ghc

I tried your fix as listed in the wiki ("...simply add one of the paths in the output of the following command to your $PATH...") and added the path from the output to the PATH via (setenv "PATH" ...); but the same path already was part of it, and it didn't fix anything.

Am I missing something?