Build

task build

task build

Runs scripts/build.sh, which:

1. compiles the host bin/rc for the current system, with CGO_ENABLED=0 (libkrun is loaded through purego at runtime);
2. compiles the guest bin/rc-guest-linux-<arch> from ./cmd/runner-guest: always Linux, static, same architecture as the host — libkrun does not emulate another architecture;
3. fails if the guest comes out dynamic, because a dynamic binary does not run in the musl image (not found);
4. on macOS, signs the host with codesign and the com.apple.security.hypervisor entitlement (build/hv.entitlements). Without it, krun_start_enter fails.

The version stamped into the binaries comes from VERSION or from git describe; without git, dev. It is what shows up in GET /health.

Why two binaries

purego forces dynamic linking against glibc on Linux. The language images are Alpine (musl). That is why the guest is a separate main, without purego, compiled statically.

task image:build

task image:build -- --stack python
task image:build -- --all

Depends on task build (the guest must exist to be injected). See image and Images.

Installing libkrun

task krun:install

System	How
macOS	task krun:install: libkrun 1.19.6 / libkrunfw 5.6.2 from the derivations in nix/
Linux	task krun:install: libkrun / libkrunfw from nixpkgs, with virtio-blk enabled

Both install .#krun into the Nix profile (~/.nix-profile/lib), where rc looks by default.

Windows

There is no Windows build. Compiling for windows/amd64 fails on purpose, with a message stating the reason (upstream libkrun has no WHP backend). The task test:targets gate checks that this rejection keeps happening.