--- a/doc/building.html	Mon Dec 17 09:35:15 2018 -0800
+++ b/doc/building.html	Wed Dec 19 00:50:05 2018 -0800
@@ -206,6 +206,7 @@
 <h4 id="windows-subsystem-for-linux-wsl">Windows Subsystem for Linux (WSL)</h4>
 <p>Only Windows 10 1803 or newer is supported due to a dependency on the wslpath utility and support for environment variable sharing through WSLENV.</p>
 <p>You may build both Windows and Linux binaries from WSL. To build Windows binaries, you must use a Windows boot JDK (located in a Windows-accessible directory). To build Linux binaries, you must use a Linux boot JDK. The default behavior is to build for Windows. To build for Linux, pass <code>--build=x86_64-unknown-linux-gnu</code> and <code>--host=x86_64-unknown-linux-gnu</code> to <code>configure</code>.</p>
+<p>If building Windows binaries, you must also have synced down the OpenJDK source code from Windows. This is because Windows executables (such as Visual Studio and the boot JDK) must be able to access the source code. Also, the directory where the OpenJDK source code is stored must be case-insensitive (either by setting the individual directory as case insensitive using fsutil, changing /etc/fstab to mount the drive as case-insensitive, or editing /etc/wsl.conf to mark all mounted Windows drives as case-insensitive).</p>
 <h4 id="cygwin">Cygwin</h4>
 <p>A functioning <a href="http://www.cygwin.com/">Cygwin</a> environment is thus required for building the JDK on Windows. If you have a 64-bit OS, we strongly recommend using the 64-bit version of Cygwin.</p>
 <p><strong>Note:</strong> Cygwin has a model of continuously updating all packages without any easy way to install or revert to a specific version of a package. This means that whenever you add or update a package in Cygwin, you might (inadvertently) update tools that are used by the JDK build process, and that can cause unexpected build problems.</p>