Thanks to Andrew Luo (and the JDK build team), it is now possible to build OpenJDK with Windows Subsystem for Linux on Windows 10 (1809+). This post will also use the JDK mirror at Github (if it is not synchronised, see the previous post for using Mercurial).

2019-01-19: added the Mercurial instructions

1. Activate Windows Subsystem for Linux
   In an administrative Powershell:

   Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux

   Restart then install, say, Ubuntu from the Windows Store

   Then launch wsl and complete the inialisation.
   See Microsoft documentation for the full instructions

2. Create a C:\dev\ directory 

3. Download and install Git (or/and Mercurial)

4. Download OpenJDK 11 and extract it to C:\dev\jdk-11.0.1

5. Download and install Visual Studio 2017 Build Tools (when installing select the Visual C++ Build Tools, and ensure the language module is English (only))

6. In a WSL console select the following packages

   sudo apt install autoconf
   sudo apt install make
   sudo apt install zip

    (unzip will be installed with zip)

7. Get OpenJDK’s source:
   in a (cmd) console:

   cd C:\dev
   git clone https://github.com/openjdk/jdk.git

   or if it is not up to date:

   hg clone http://hg.openjdk.java.net/jdk/jdk/

   alternatively instead of attempting to clone from hg.openjdk.java.net (especially from Europe), download and extract Alexsey Shipilev’s https://builds.shipilev.net/workspaces/jdk-jdk.tar.xz then extract in C:\dev\jdk then

   cd C:\dev
   hg pull
   hg update

8. Build OpenJDK
   in a (wsl) console:

   cd /mnt/c/dev/jdk
   bash configure –with-boot-jdk=/mnt/c/dev/jdk-11.0.1/ –disable-warnings-as-errors
   make images

   (–disable-warnings-as-errors so that VS2017 warnings are not stopping the build)

9. Test it
   in a (cmd) console:

   C:\dev\jdk\build\windows-x86_64-server-release\images\jdk\bin\java –version

10. hack!

See the JDK’s building.md document for more information.