hadrian: Offer a flag to print out the compiler invokation for a target
At the moment, whenever I want to check compilation of a single module, say, in base, I have to
- Change that module's source file, e.g. by inserting a
{-# OPTIONS_GHC -ddump-simpl -ddump-to-file #-}pragma - Run hadrian with
-VV - Be quick to cancel the build when the interesting invokation is shown
- Put up with having to rebuild the whole compiler.
When all I want is a command-line that I can tweak to my liking, perhaps by substituting the *.hs file for a local test-copy and replacing -o directives so that indeed the build directory is untouched.