When compiling a C++ program with GCC4, there is no error shown if the linker (ld.exe) returns 1. For example, this is the case when your program is running and the linker tries to overwrite it.
The console output is marked red in the "Build log", but the message pane auto-hides and no error is shown in the build messages ("Build finished: 0 errors, 4 warnings").
Console output:
[......]
d:/c++/mingw/bin/../lib/gcc/mingw32/4.3.0/../../../../mingw32/bin/ld.exe: cannot open output file ..\utf8-coding.exe: Permission denied
collect2: ld returned 1 exit status
Process terminated with status 1 (0 minutes, 2 seconds)
0 errors, 4 warnings
I'm using nightly build 5000.
Do you have the same problem? Probably even with other compilers? It might be a bug, then...