Cross-Compiling-for-Debian-Based-Linux.md

To build for a target architecture different than the host (e.g. using x64 to build for ARM), you'll need to do the following, in addition to the setup under How to Contribute:

One-Time Setup

1. Install build toolchain and chroot/rootfs prerequisites:

   sudo apt-get install qemu qemu-user-static debootstrap gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf

2. Create a chroot/rootfs for the target architecture:

   sudo qemu-debootstrap --arch=armhf --variant=minbase xenial rootfs

3. Install libx11-dev on the chroot/rootfs:

   sudo chroot rootfs apt-get install -y libx11-dev

Build

Because cross-compiling isn't officially supported by the VSCode team, some workarounds are required to make the app build correctly:

1. Point to the target toolchain on the build host:

   export CC=$(which arm-linux-gnueabihf-gcc)
   export CXX="$(which arm-linux-gnueabihf-g++) -L$(pwd)/rootfs/usr/lib/arm-linux-gnueabihf/"

   note the -L linker argument pointing to the absolute path of libx11 on the chroot/rootfs

2. Remove the yarn check, since yarn doesn't currently support cross-compiling:

   echo > build/npm/preinstall.js

3. Set the electron version and install prerequisites for the target architecture using npm (instead of yarn):

   export npm_config_target="$(grep target .yarnrc | sed 's/[^0-9.]*//g')"
   npm install --target_arch=armhf

4. Build VSCode and create a .deb file (for easier installation on the target device) as usual:

   yarn run gulp vscode-linux-arm-min
   yarn run gulp vscode-linux-arm-build-deb