pygtk: add PYTHONPATH caveats

Closes #10905.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/Library/Formula/pygtk.rb b/Library/Formula/pygtk.rb
index 3632f5d1d..dbfa4c410 100644
--- a/Library/Formula/pygtk.rb
+++ b/Library/Formula/pygtk.rb
@@ -22,6 +22,16 @@ class Pygtk < Formula
     system "make install"
   end
 
+  def caveats; <<-EOS.undent
+    For non-Homebrew Python, you need to amend your PYTHONPATH like so:
+      export PYTHONPATH=#{HOMEBREW_PREFIX}/lib/#{which_python}/site-packages:$PYTHONPATH
+    EOS
+  end
+
+  def which_python
+    "python" + `python -c 'import sys;print(sys.version[:3])'`.strip
+  end
+
   def test
     mktemp do
       (Pathname.pwd+'test.py').write <<-EOS.undent