Hi, The error message is the following: Creating library file: .libs/libMonoPosixHelper.dll.a .libs/signal.o: In function `Mono_Posix_Syscall_psignal': /mono/mono/support/signal.c:47: undefined reference to `_psignal' I think Mono_Posix_Syscall_psignal is not required on Win32 and should not be compiled on PLATFORM_WIN32. Kornél