Speed up the build

When you build WebKitGTK or WPEWebKit using the Flatpak SDK, ccache is enabled by default. More options are available, for distributed builds. See below.

sccache

​sccache is available in the SDK. Depending on your sccache-dist cloud deployment, you might need to ask for an authentication token to your sysadmin. Once you have it, generate the toolchain archives that will be used for the distributed compilation:

$ Tools/Scripts/webkit-flatpak -r -t token -s scheduler-url

By default the scheduler url is Igalia's if it wasn't provided on the command-line.

Once the toolchains have been generated, they will be available in WebKitBuild/Toolchains/ and a sccache config file should be present in WebKitBuild/UserFlatpak/sccache.toml. Feel free to edit it, but keep in mind this is a generated file. To use a custom config file during the build, use the $SCCACHE_CONF env var (refer to the upstream sccache docs), otherwise the generated one will be used by default.

The next step is to enable sccache in your build:

export WEBKIT_USE_SCCACHE=1
export NUMBER_OF_PROCESSORS=45

And then run build-webkit as usual. Open a network traffic monitor and watch for the uplink data rate. For debug builds a good downlink is needed as well, because the object files produced on the cloud builders are bigger.

IceCC

TODO