WINDOWS BUILD NOTES

 Below are some notes on how to build Bitcoin Core for Windows. The options known to work for building Bitcoin Core on Windows are:  

  On Linux using the Mingw-w64 cross compiler tool chain. Ubuntu Trusty 14.04 is recommended and is the platform used to build the Bitcoin Core Windows release binaries.

   On Windows using Windows Subsystem for Linux (WSL) and the Mingw-w64 cross compiler tool chain.

Other options which may work but which have not been extensively tested are (please contribute instructions):  

  On Windows using a POSIX compatibility layer application such as cygwin or msys2.

   On Windows using a native compiler tool chain such as Visual Studio.

Installing Windows Subsystem for Linux With Windows 10, Microsoft has released a new feature named the  Windows Subsystem for Linux (WSL). This feature allows you to run a bash  shell directly on Windows in an Ubuntu-based environment. Within this  environment you can cross compile for Windows without the need for a  separate Linux VM or server. Note that while WSL can be installed with  other Linux variants, such as OpenSUSE, the following instructions have  only been tested with Ubuntu. This feature is not supported in versions of Windows prior to  Windows 10 or on Windows Server SKUs. In addition, it is available only  for 64-bit versions of Windows. Full instructions to install WSL are available on the above link.  To install WSL on Windows 10 with Fall Creators Update installed  (version >= 16215.0) do the following:  

  Enable the Windows Subsystem for Linux feature

  From Start, search for "Turn Windows features on or off" (type 'turn')

   Select Windows Subsystem for Linux

   Click OK

   Restart if necessary

  Install Ubuntu

  Open Microsoft Store and search for Ubuntu or use this link

   Click Install

  Complete Installation

  Open a cmd prompt and type "Ubuntu"

   Create a new UNIX user account (this is a separate account from your Windows account)

After the bash shell is active, you can follow the instructions  below, starting with the "Cross-compilation" section. Compiling the  64-bit version is recommended but it is possible to compile the 32-bit  version. Cross-compilation for Ubuntu and Windows Subsystem for Linux At the time of writing the Windows Subsystem for Linux installs  Ubuntu Xenial 16.04. The Mingw-w64 package for Ubuntu Xenial does not  produce working executables for some of the Bitcoin Core applications.  It is possible to build on Ubuntu Xenial by installing the cross  compiler packages from Ubuntu Zesty, see the steps below. Building on  Ubuntu Zesty 17.04 up to 17.10 has been verified to work. The steps below can be performed on Ubuntu (including in a VM) or  WSL. The depends system will also work on other Linux distributions,  however the commands for installing the toolchain will be different. First, install the general dependencies:  

sudo apt install build-essential libtool autotools-dev automake pkg-config bsdmainutils curl git

A host toolchain (build-essential) is necessary because some  dependency packages (such as protobuf) need to build host utilities that  are used in the build process. See also: dependencies.md. Building for 64-bit Windows The first step is to install the mingw-w64 cross-compilation tool  chain. Due to different Ubuntu packages for each distribution and  problems with the Xenial packages the steps for each are different. Common steps to install mingw32 cross compiler tool chain:  

sudo apt install g++-mingw-w64-x86-64

Ubuntu Trusty 14.04: No further steps required Ubuntu Xenial 16.04 and Windows Subsystem for Linux 1,2:  

sudo apt install software-properties-common

sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu zesty universe"

sudo apt update

sudo apt upgrade

sudo update-alternatives --config x86_64-w64-mingw32-g++ # Set the default mingw32 g++ compiler option to posix.

Ubuntu Zesty 17.04 2:  

sudo update-alternatives --config x86_64-w64-mingw32-g++ # Set the default mingw32 g++ compiler option to posix.

Once the tool chain is installed the build steps are common: Note that for WSL the Bitcoin Core source path MUST be somewhere  in the default mount file system, for example /usr/src/bitcoin, AND not  under /mnt/d/. If this is not the case the dependency autoconf scripts  will fail. This means you cannot use a directory that located directly  on the host Windows file system to perform the build. The next three steps are an example of how to acquire the source in an appropriate way.  

cd /usr/src

sudo git clone https://github.com/bitcoin/bitcoin.git

sudo chmod -R a+rw bitcoin

Once the source code is ready the build steps are below.  

PATH=$(echo "$PATH" | sed -e 's/:\/mnt.*//g') # strip out problematic Windows %PATH% imported var

cd depends

make HOST=x86_64-w64-mingw32

cd ..

./autogen.sh # not required when building from tarball

CONFIG_SITE=$PWD/depends/x86_64-w64-mingw32/share/config.site ./configure --prefix=/

make

Building for 32-bit Windows To build executables for Windows 32-bit, install the following dependencies:  

sudo apt install g++-mingw-w64-i686 mingw-w64-i686-dev

For Ubuntu Xenial 16.04, Ubuntu Zesty 17.04 and Windows Subsystem for Linux 2:  

sudo update-alternatives --config i686-w64-mingw32-g++  # Set the default mingw32 g++ compiler option to posix.

Note that for WSL the Bitcoin Core source path MUST be somewhere in  the default mount file system, for example /usr/src/bitcoin, AND not  under /mnt/d/. If this is not the case the dependency autoconf scripts  will fail. This means you cannot use a directory that located directly  on the host Windows file system to perform the build. The next three steps are an example of how to acquire the source in an appropriate way.  

cd /usr/src

sudo git clone https://github.com/bitcoin/bitcoin.git

sudo chmod -R a+rw bitcoin

Then build using:  

PATH=$(echo "$PATH" | sed -e 's/:\/mnt.*//g') # strip out problematic Windows %PATH% imported var

cd depends

make HOST=i686-w64-mingw32

cd ..

./autogen.sh # not required when building from tarball

CONFIG_SITE=$PWD/depends/i686-w64-mingw32/share/config.site ./configure --prefix=/

make

Depends system For further documentation on the depends system see README.md in the depends directory. Installation After building using the Windows subsystem it can be useful to  copy the compiled executables to a directory on the windows drive in the  same directory structure as they appear in the release .zip archive.  This can be done in the following way. This will install to  c:\workspace\bitcoin, for example:  

make install DESTDIR=/mnt/c/workspace/bitcoin

Footnotes 1: There is currently a bug in the 64 bit Mingw-w64 cross  compiler packaged for WSL/Ubuntu Xenial 16.04 that causes two of the  bitcoin executables to crash shortly after start up. The bug is related  to the -fstack-protector-all g++ compiler flag which is used to mitigate  buffer overflows. Installing the Mingw-w64 packages from the Ubuntu 17  distribution solves the issue, however, this is not an officially  supported approach and it's only recommended if you are prepared to  reinstall WSL/Ubuntu should something break. 2: Starting from Ubuntu Xenial 16.04 both the 32 and 64 bit  Mingw-w64 packages install two different compiler options to allow a  choice between either posix or win32 threads. The default option is  win32 threads which is the more efficient since it will result in binary  code that links directly with the Windows kernel32.lib. Unfortunately,  the headers required to support win32 threads conflict with some of the  classes in the C++11 standard library in particular std::mutex. It's not  possible to build the bitcoin code using the win32 version of the  Mingw-w64 cross compilers (at least not without modifying headers in the  bitcoin source code).