mono build on cygwin have error ,how to do build? - mono

Question

I do it according to the instructions by (http://www.mono-project.com/docs/compiling-mono/windows/)
PATH=$PREFIX/bin:$PATH
git clone https://github.com/mono/mono.git
cd mono
do shell cmd ./autogen.sh --prefix=$PREFIX --host=x86_64-w64-mingw32 --disable-boehm
Git submodules updated successfully
mcs source: mcs
C# Compiler: roslyn
Engine:
Host: x86_64-w64-mingw32
Target: x86_64-w64-mingw32
GC: sgen (concurrent by default)
TLS: pthread
SIGALT STACK: no
Engine: Building and using the JIT
BigArrays: no
DTrace: no
LLVM Back End: no (dynamically loaded: no)
Libraries:
.NET 4.x: yes
Xamarin.Android: no
Xamarin.iOS: no
Xamarin.WatchOS: no
Xamarin.TVOS: no
Xamarin.Mac: no
Windows AOT: no
Orbis: no
Unreal: no
WebAssembly: no
Test profiles: AOT Full (no), AOT Hybrid (no)
JNI support: no
libgdiplus: assumed to be installed
zlib:
BTLS: no
jemalloc: no (always use: no)
Now type `make' to compile
do make and then have below error
C:/cygwin64/home/Administrator/mono/mono/mini/mono-sgen.exe:
error while loading shared libraries: ?: cannot open shared object file: No such file or directory
make[8]: *** [il.make:4：../../../class/lib/basic/corlib.unsafe.dll.tmp] 错误 127
make[7]: *** [../../../build/rules.make:211：do-all] 错误 2
make[6]: *** [../build/rules.make:232：all-recursive] 错误 1
make[5]: *** [build/rules.make:232：all-recursive] 错误 1
make[4]: *** [Makefile:54：profile-do--basic--all] 错误 2
make[3]: *** [Makefile:50：profiles-do--all] 错误 2
make[2]: *** [Makefile:613：all-local] 错误 2
make[2]: 离开目录“/home/Administrator/mono/runtime”
make[1]: *** [Makefile:558：all-recursive] 错误 1
make[1]: 离开目录“/home/Administrator/mono”
make: *** [Makefile:488：all] 错误 2

Answer 1

I have hit this myself twice, but... you aren't supposed to run that thing, actually. You use msbuild to build mono.exe and run make to build the BCL.
The problem you are seeing, is that, in following the directions, you have cross built a mingw mono.exe from a cygwin host. I know, they seem like the same thing, but they aren't quite. The mingw mono.exe fails to run in cygwin environment because it doesn't find libgcc_s.dll or so, and maybe others.
If you dir /s/b C:\cygwin64\libgcc*.dll and notice the mingw sysroot, you can add that directory or directories to your %PATH%, and then this mingw mono.exe will work. However, the right solution is probably a proper mingw install, not using the sysroot, and again, this mono.exe isn't the goal.
Once you use msbuild, you get native Visual C++, and its symbols, and its debugger or windbg, and therein to me is one of the huge values of windows -- the debuggers -- which cygwin and mingw don't give you.

Answer 2

Try to execute C:/cygwin64/home/Administrator/mono/mono/mini/mono-sgen.exe directly - it should complain it misses some cygwin files - copy them to this folder

Answer 3

It doesn't work because the mingw .dlls aren't in $PATH.
You have cross-build a mingw mono from Cygwin environment.
I strongly recommend though you use msbuild against the msvc/*.sln file instead, using Visual C++ instead of mingw to build, and thereby the Visual Studio and windbg debuggers work.