vcs.rb: debug print in system method

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62058 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 8 insertions, 0 deletions

diff --git a/tool/vcs.rb b/tool/vcs.rb
index c3a5b3a0f8..629d521320 100644
--- a/tool/vcs.rb
+++ b/tool/vcs.rb
@@ -86,6 +86,14 @@ else
         super
       end
     end
+    refine Kernel do
+      def system(*args, exception: true, **opts)
+        STDERR.puts [*args, **opts].inspect if $DEBUG
+        ret = super(*args, **opts, exception: exception)
+        raise "Command failed with status (#$?): #{args[0]}" if exception and !ret
+        ret
+      end
+    end
   ensure
     $VERBOSE = verbose unless verbose.nil?
   end