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test.exe - Application Error
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The application was unable to start correctly (0xc0000142). Click OK to close the application.
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OK
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This is on Windows 8, wx-0.90.0.1, wxc-0.90.0.4, wxcore-0.90.0.3, wxdirect-0.90.0.1, wxWidgets 2.9.4. wxWidgets C++ samples compiled with mingw do not have this error. Programs compiled with old wxhaskell (latest version to support wxWidgets 2.8) do work.
This might be because of missing DLLs, see
http://www.haskell.org/haskellwiki/WxHaskell/Windows#DLLs
Or the MinGW/gcc was too new (the DLLs generated by a recent version of gcc seem to be incompatible with the binaries compiled by the gcc that comes with GHC).