Blacklist libv8 version that breaks mini_racer

Gemfile

@@ -88,6 +88,9 @@ group :assets do
   gem 'coffee-rails', '~> 3.2.1'
 
   gem 'mini_racer'
+  # We found that the following version of libv8 breaks the compilation of mini_racer.
+  # Nothing else depends on libv8.
+  gem 'libv8', '!= 6.7.288.46.1'
 
   gem 'uglifier', '>= 1.0.3'
 

Gemfile.lock

@@ -757,6 +757,7 @@ DEPENDENCIES
   jwt (~> 1.5)
   knapsack
   letter_opener (>= 1.4.1)
+  libv8 (!= 6.7.288.46.1)
   listen (= 3.0.8)
   mini_racer
   momentjs-rails