Compiling Mono on Windows
To build Mono on Windows, a Cygwin setup is required since it provides some tools required by Mono at build time. You’ll also need Visual Studio 2017 or later installed.
Developer Modein the Windows 10 Settings app (Update & Security -> For developers tab)
- Download and install 64 bit Cygwin from www.cygwin.com.
- Install Visual Studio 2017 or later - Community Edition works fine.
- Download and install Mono for Windows or use
monolitebuild step as described below.
- Run the following command in cmd.exe to install the required packages:
setup-x86_64.exe -P autoconf,automake,bison,gcc-core,gcc-g++,mingw64-i686-runtime,mingw64-i686-binutils,mingw64-i686-gcc-core,mingw64-i686-gcc-g++,mingw64-i686-pthreads,mingw64-i686-w32api,mingw64-x86_64-runtime,mingw64-x86_64-binutils,mingw64-x86_64-gcc-core,mingw64-x86_64-gcc-g++,mingw64-x86_64-pthreads,mingw64-x86_64-w32api,libtool,make,python,gettext-devel,gettext,intltool,libiconv,pkg-config,git,curl,wget,libxslt,bc,patch,cmake
Make sure that the following GIT setting is set to avoid issues with line endings:
git config --global core.autocrlf input
Building Mono from a Release Package
Mono releases are distributed as .tar.bz2 packages from the Mono web site. Once you have your dependencies installed all you need to do is run the following command where VERSION is the package version number and PREFIX is your installation prefix:
PREFIX=/usr/local VERSION=4.2.1 tar xvf mono-$VERSION.tar.bz2 cd mono-$VERSION
And then you can continue with the appropriate commands below, without running git clone and cd mono.
Build Mono 64-bit using Visual Studio
The native runtime libraries can be built using Visual Studio and msbuild. However the .NET libraries and tests must currently be built in cygwin using make. The steps below describe how you use cygwin to first configure the build, then build the runtime libraries in Visual Studio and use the Visual Studio built mono executable when building the class libraries and tests in cygwin.
Below we specify 64-bit build and sgen GC (The boehm GC is not supported on 64-bit windows), installing build into
$PREFIX where mono distribution already exists (replacing). NOTE, in order to keep existing mono distribution untouched, setup a different
$PREFIX. You may also only set
PATH to point to existing mono distribution and not specify
$PREFIX at all.
PATH=$PREFIX/bin:$PATH git clone https://github.com/mono/mono.git cd mono ./autogen.sh --prefix=$PREFIX --host=x86_64-w64-mingw32 --disable-boehm
To build Mono 32-bit, run autogen with
--host=i686-w64-mingw32 instead and choose 32-bit when building in Visual Studio.
Now open the mono solution
msvc\mono.sln in Visual Studio. Rebuild the solution and point the
MONO_EXECUTABLE to the mono exe you just built in Visual Studio. Eg:
if you built 64-bit Release version.
Command line using msbuild.exe
Instead of building from within Visual Studio you can use
msbuild.exe directly in the cygwin terminal:
/cygdrive/c/Program\ Files\ \(x86\)/MSBuild/14.0/Bin/MSBuild.exe /p:PlatformToolset=v140 /p:Platform=x64 /p:Configuration=Release /p:MONO_TARGET_GC=sgen msvc/mono.sln
Use desired parameters in the Platform and Configuration parameters to change between 64 and 32 bit builds as well as Release and Debug builds.
If only changes has been done to the native code and no changes have been done to base class libraries or .NET tests, building/rebuilding using Visual Studio solution is enough. If, however there are changes done to the base class libraries or tests, you need to run make in cygwin to rebuild the class libraries and/or tests.
Building without installed Mono distribution
If no Mono distribution is installed, you can build using
monolite. Just run the below before running
Next step is to build the BCL and all System libraries. Go back to cygwin and run make:
make make install
It is possible to parallelize the cygwin build passing in for example
-j8, where 8 in this case is the number of parallel builders to run.
Known Issue: “failed to create symbolic link”
If you run
make V=1 and see this after a successful BCL build:
make: Entering directory '/home/user/work/mono/mcs/class/corlib' CYGWIN=winsymlinks:nativestrict ln -s /home/user/work/mono/mcs/class/lib/build-win32 /home/user/work/mono/mcs/class/lib/build ln: failed to create symbolic link '/home/user/work/mono/mcs/class/lib/build': Operation not permitted make: *** [../../build/library.make:336: ../../class/lib/build/.stamp] Error 1
you need to enable
Developer Mode in the Windows 10 Settings app (Update & Security -> For developers tab) which will allow your user to create symbolic links without administrator privileges.
If you use an earlier Windows versions you need to run the build as administrator.
Building with Windows Subsystem for Linux (WSL)
Normally you should be able to just use the Linux instructions. Currently your
configure invocations must include
--with-csc=mcs, as building with Roslyn triggers as severe (system-crashing) known issue.