gistfile1.sh

$ heroku run bash
Running `bash` attached to terminal... up, run.1256
~ $ cd sbcl/sbcl-1.0.54-x86-64-linux/

~/sbcl/sbcl-1.0.54-x86-64-linux $ chmod +x run-sbcl.sh 

~/sbcl/sbcl-1.0.54-x86-64-linux $ ./run-sbcl.sh 

(running SBCL from: /app/sbcl/sbcl-1.0.54-x86-64-linux)
This is SBCL 1.0.54, an implementation of ANSI Common Lisp.
More information about SBCL is available at <http://www.sbcl.org/>.

SBCL is free software, provided as is, with absolutely no warranty.
It is mostly in the public domain; some portions are provided under
BSD-style licenses.  See the CREDITS and COPYING files in the
distribution for more information.

* (require 'sb-posix)

("SB-POSIX" "SB-GROVEL" "ASDF")
* (sb-posix:getenv "PWD")

"/app/sbcl/sbcl-1.0.54-x86-64-linux"
*