I don't see why the "-m windows" option is required at all, especially since it is ignored by MingW's GNU make.

Regarding the Qt dependency:
Qt Code: 
  1. CONFIG -= qt
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suppresses Qt libraries, and:
Qt Code: 
  1. CONFIG -= console
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to suppress the console on Windows (although it may be suppressed just by excluding Qt libraries). The app_bundle option only means something on Mas OS X.