mach.bat run doesn't show output on windows

[jdm]

The following patch makes it appear when Servo panics:

diff --git a/python/servo/post_build_commands.py b/python/servo/post_build_commands.py
index 6e8c65e..20d031b 100644
--- a/python/servo/post_build_commands.py
+++ b/python/servo/post_build_commands.py
@@ -142,8 +142,9 @@ class PostBuildCommands(CommandBase):
             args = args + params

         try:
-            check_call(args, env=env)
+            check_output(args, env=env)
         except subprocess.CalledProcessError as e:
+            print(e.output)
             print("Servo exited with return value %d" % e.returncode)
             return e.returncode
         except OSError as e:

[highfive]

cc @wafflespeanut

[tigercosmos]

Why not open a PR?

[jdm]

It doesn't make ./mach run work when Servo does not panic.