option to accept ISO C99... unsupported

Tried to build Haskell under cygwin under Windows 10 (x86_64) but /configure failed. I had a look on google and through the bug tracker but could not find anything helpful.

Note that in the output from ./configure check two versions of gcc.exe

1. ... /ghc/inplace/mingw/bin/gcc.exe
2. C:/Program Files/Haskell Platform/8.0.1/lib/../mingw/bin/gcc.exe

The check for the first succeeds but that for the second fails yet they both seem to be the same version of gcc.exe: (realgcc.exe (Rev3, Built by MSYS2 project) 5.2.0)

checking for C:/unix/cygwin64/home/jb/haskell/ghc/inplace/mingw/bin/gcc.exe option to accept ISO C99... none needed
checking for C:/Program Files/Haskell Platform/8.0.1/lib/../mingw/bin/gcc.exe option to accept ISO C99... unsupported

$ C:/unix/cygwin64/home/jb/haskell/ghc/inplace/mingw/bin/gcc.exe --version
realgcc.exe (Rev3, Built by MSYS2 project) 5.2.0
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

jb@fabulord ~/haskell/ghc
$ "C:/Program Files/Haskell Platform/8.0.1/lib/../mingw/bin/gcc.exe" --version
realgcc.exe (Rev3, Built by MSYS2 project) 5.2.0
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Build System
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