protobuf: complain if dateutil is too new

Closes #33124. Closes #33045. Fixes #32571.

1 files changed, 35 insertions, 0 deletions

diff --git a/Library/Formula/protobuf.rb b/Library/Formula/protobuf.rb
index a3e531c1a..9ea2f7651 100644
--- a/Library/Formula/protobuf.rb
+++ b/Library/Formula/protobuf.rb
@@ -1,5 +1,39 @@
 require 'formula'
 
+class OldOrNoDateutilUnlessGoogleApputils < Requirement
+  # https://github.com/Homebrew/homebrew/issues/32571
+  # https://code.google.com/p/google-apputils-python/issues/detail?id=6
+  fatal true
+
+  satisfy(:build_env => false) {
+    if can_import("dateutil") && !can_import("google.apputils")
+      dateutil_version < Version.new("2.0")
+    else
+      true
+    end
+  }
+
+  def message; <<-EOS.undent
+    The protobuf Python bindings depend on the google-apputils Python library,
+    which requires a version of python-dateutil less than 2.0.
+
+    You have python-dateutil version #{dateutil_version} installed in:
+      #{Pathname.new(`python -c "import dateutil; print(dateutil.__file__)"`.chomp).dirname}
+
+    Please run:
+      pip uninstall python-dateutil && pip install "python-dateutil<2"
+    EOS
+  end
+
+  def can_import pymodule
+    quiet_system "python", "-c", "import #{pymodule}"
+  end
+
+  def dateutil_version
+    Version.new(`python -c "import dateutil; print(dateutil.__version__)"`.chomp)
+  end
+end
+
 class Protobuf < Formula
   homepage 'http://code.google.com/p/protobuf/'
   url 'https://protobuf.googlecode.com/svn/rc/protobuf-2.6.0.tar.bz2', :using => :curl
@@ -16,6 +50,7 @@ class Protobuf < Formula
   option :cxx11
 
   depends_on :python => :optional
+  depends_on OldOrNoDateutilUnlessGoogleApputils if build.with? "python"
 
   fails_with :llvm do
     build 2334