Comment 6 for bug 1495459

Specifically, it is the following line that triggers the problem:

$ bzr diff
=== modified file 'src/platforms/mesa/server/x11/graphics/graphics.cpp'
--- src/platforms/mesa/server/x11/graphics/graphics.cpp 2015-09-11 14:19:21 +0000
+++ src/platforms/mesa/server/x11/graphics/graphics.cpp 2015-09-14 13:40:50 +0000
@@ -66,7 +66,7 @@
 {
     config.add_options()
         (x11_displays_option_name,
- boost::program_options::value<std::string>()->default_value("1280x1024"),
+// boost::program_options::value<std::string>()->default_value("1280x1024"),
          "[mir-on-X specific] WIDTHxHEIGHT of \"display\" window.");
 }