Added some instructions for building on Linux

1 files changed, 55 insertions, 1 deletions

diff --git a/README.md b/README.md
index 055ecca3a..cde128568 100644
--- a/README.md
+++ b/README.md
@@ -59,7 +59,61 @@ It's also possible to generate project files for Visual Studio via
 
 ## Building on Linux
 
-... coming soon
+The following instructions have been collated using Ubuntu 20.04.
+
+At the time of writing only GCC v11 supports the C++20 features used by Zen. As
+this version is not available in the default package repositories we need to
+get GCC from one of Ubuntu's toolchain repositories;
+
+```
+sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+sudo apt install -y gcc-11
+gcc-11 --version
+```
+
+Next we need the `xmake` build system. For this we will download and install
+`xmake` as a `.deb` package. Check the project's release page for more up to
+date `.deb` files;
+
+```
+wget https://github.com/xmake-io/xmake/releases/download/v2.5.7/xmake-v2.5.7.amd64.deb
+sudo dpkg -i xmake-v2.5.7.amd64.deb
+xmake --version
+```
+
+For some of Zen's third party dependencies are provided by Microsoft's `vcpkg`
+C++ library manager. After cloning the project there is a initialisation step;
+
+```
+git clone https://github.com/microsoft/vcpkg.git ~/zen/vcpkg
+~/zen/vcpkg/bootstrap-vcpkg.sh
+```
+
+`xmake` uses an environment variable to find `vcpkg`. Alternatively this can be
+done by including `VCPKG_ROOT=...` on the command line when invoking `xmake`;
+
+```
+export VCPKG_ROOT=~/zen/vcpkg
+```
+
+Clone the Zen project and tell `xmake` to use the correct GCC version;
+
+```
+git clone https://github.com/EpicGames/zen.git ~/zen/main
+cd ~/zen/main
+xmake config --plat=linux --cxx=g++-11 --cc=gcc-11
+```
+
+Now we are ready to build Zen. The `--mode=debug` is optional. It has been
+included below to show how to change build variants. The `-y` skips `xmake` from
+prompting about updating `vcpkg` packages;
+
+```
+xmake config --mode=debug
+xmake build -y
+```
+
+The `xmake` flags `-vD` can be useful to diagnose `xmake` issues.
 
 ## Building on Mac