icecream!

Lots of KDE hacking these days, and that comes with compiling large amounts of code. Right now, I am installing, well building from source Plasma Mobile on an “old” laptop so I can test some patches natively on a touchscreen device. The machine has just two cores (hyperthreaded), so builds take rather long, especially if you build Qt and all that 80+ packages that are needed for a fully working Plasma system.
One of the tools that do an incredible job while being super flexible to use is icecream. Icecream (or “icecc“) allows you to distribute your build over multiple machines, it basically ships compile-jobs with all that’s needed to other machines on a local network, meaning you can parallelize your builds.

Icecream has this nice visualization tool, called icecream-monitor which you can stare at while your builds are running (in case you don’t have anyone handy for a sword-fight). In the screenshot you can see manta, the underpowered laptop doing a 32 parallel job build over the network. miro is my heavy workstation, 8 cores and 128GB of RAM, it duely gets the bulk of the work assigned, frame is my (Framework) laptop, which is also quite beefy, gets something to do too, but not taxed as heavily as that build monster in my basement office.
Icecream can be used with most environments that have you run your compiler locally. Different distros are no problem! Just a matching CPU architecture is needed. Icecream does its job by providing its own g++ and gcc binaries, which will relay the build jobs transparently to either your local machine or across the network. So you basically install it, adjust your PATH variable to make sure icecc’s g++ is found before your system’s compiler and start your build. Other machines you want to join in for the fun just need to run icecc-scheduler and they will be automatically discovered as build slaves on your network. If you want to further speed up builds, it works with ccache as well.

Please note that you only want to do this in a trusted environment, we’re shipping executables around the network without authorization!