I’ve been playing around with a local test of hydra, trying to build a 20.09 small release.nix.
Many jobs complete, however 30 jobs fail with Unsupported build type 
I presume this is local configuration problem. They seem to stem from this build but the might not be relevant.
due to a brainfreeze I forgot to configure my builders. Each builder , be it local or remote needs to be configured, so hydra can work out what capablities the builder has.
an addition to the configuration.nix
nix.buildMachines = [
{ hostName = “localhost”;
system = “x86_64-linux”;
supportedFeatures = [“kvm” “nixos-test” “big-parallel” “benchmark”];
maxJobs = 8;
}
];
and the tests run.
I presume for kvm, a machine will have to be have to be configured for kvm virualisations, rather than the vanilla qemu.
Also this is a just a test , you wouldn’t really run tests on local host, i presume bad things can happen… but @grahamc can probably shed more light on it.
It is definitely okay to have localhost be a “remote” builder for small Hydra machines. For bigger Hydras, the main machine is going to be quite busy with memory and IO: evaluating, copying build results, and uploading to a binary cache (or writing to local disk.)
I wonder if this could be made clearer, maybe by changing the message to have an alt text that says no builders for this architecture are available?
