GHC 2017-12-13

2017-12-13 00:19:19, https://git.io/vbgmg in Homebrew/homebrew-core

(Anyway, py27 EOL is, interestingly, only 27 months away, so if we just wait it out it will resolve itself in 27 months...)

2017-12-13 00:17:19, https://git.io/vbgm2 in Homebrew/homebrew-core

I did not look at the details of this issue, but my former, detailed analysis of the python3-as-default situation is https://github.com/Homebrew/brew/issues/2958. Never got around to working on a fix though. I've been sporting this patch the whole time:

```diff
diff --git a/Library/Homebrew/requirements/python_requirement.rb b/Library/Homebrew/requirements/python_requirement.rb
index c162b072c9..5223455a13 100644
--- a/Library/Homebrew/requirements/python_requirement.rb
+++ b/Library/Homebrew/requirements/python_requirement.rb
@@ -46,7 +46,7 @@ class PythonRequirement < Requirement
   end
 
   def python_binary
-    "python"
+    "python2.7"
   end
 
   # Deprecated
```