can't get wxHaskell to work from ghci on Mac

Question

I'm trying to run an example using EnableGUI function.

% ghci -framework Carbon Main.hs

*Main> enableGUI >> main

This is what I get instead of a working program:

2013-01-14 00:21:03.021 ghc[13403:1303] *** Assertion failure in +[NSUndoManager _endTopLevelGroupings], /SourceCache/Foundation/Foundation-945.11/Misc.subproj/NSUndoManager.m:328
2013-01-14 00:21:03.022 ghc[13403:1303] +[NSUndoManager(NSInternal) _endTopLevelGroupings] is only safe to invoke on the main thread.
2013-01-14 00:21:03.024 ghc[13403:1303] (
    0   CoreFoundation                      0x00007fff8c8ea0a6 __exceptionPreprocess + 198
    1   libobjc.A.dylib                     0x00007fff867243f0 objc_exception_throw + 43
    2   CoreFoundation                      0x00007fff8c8e9ee8 +[NSException raise:format:arguments:] + 104
    3   Foundation                          0x00007fff884966a2 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 189
    4   Foundation                          0x00007fff884fc8b7 +[NSUndoManager(NSPrivate) _endTopLevelGroupings] + 156
    5   AppKit                              0x00007fff8ecb832d -[NSApplication run] + 687
    6   libwx_osx_cocoau_core-2.9.4.0.0.dylib 0x000000010ae64c96 _ZN14wxGUIEventLoop5DoRunEv + 40
    7   libwx_baseu-2.9.4.0.0.dylib         0x000000010b37e0e5 _ZN13wxCFEventLoop3RunEv + 63
    8   libwx_baseu-2.9.4.0.0.dylib         0x000000010b2e91bf _ZN16wxAppConsoleBase8MainLoopEv + 81
    9   libwx_osx_cocoau_core-2.9.4.0.0.dylib 0x000000010ae1b04f _ZN5wxApp5OnRunEv + 29
    10  libwx_baseu-2.9.4.0.0.dylib         0x000000010b32e8d1 _Z7wxEntryRiPPw + 102
    11  libwxc.dylib                        0x000000010bc8a9a4 ELJApp_InitializeC + 116
    12  ???                                 0x000000010beb9702 0x0 + 4494956290
)
2013-01-14 00:21:03.024 ghc[13403:1303] *** Assertion failure in +[NSUndoManager _endTopLevelGroupings], /SourceCache/Foundation/Foundation-945.11/Misc.subproj/NSUndoManager.m:328

When I'm compile and macosx-app it, it works rather well, but, for obvious reasons, I really want this to work from ghci.

What can I do? Google reveals nothing about the misterious problems of NSUndoManager used with Haskell. :(

Inalterable

Answer 1

ghci -fno-ghci-sandbox

works for me on OSX 10.8 , wx 0.90.0.1

thanks to Heinrich :https://github.com/jodonoghue/wxHaskell/pull/6

Madagascar

adding ghc-options: -fno-ghci-sandbox in the cabal file / (Executable section) make is work in Leksah / ghci - debugger too. – Madagascar

Just tried and confirmed ghc-options: -fno-ghci-sandbox solves the problem. Thanks Luc Taesch! – Succession

Answer 2

wxHaskell hasn't worked within ghci for a while. Apparently C++ memory management and re-using components within ghci causes problems. You juat have to rewrite main repeatedly. :(

The faq says

GHCi cannot mix static and dynamic libraries; it will be solved in the near future in wxHaskell.

Disproportionation