🤖 Toolchains

Installed on docs-t1 (x86-64, Debian 13) under $HOME, with no sudo, by scripts/toolchains.sh. Put them on PATH with source scripts/env.sh. Carloku runs linux-arm64, so each language also needs a way to produce a static (or libc-only) arm64 binary. scripts/smoke.sh <lang> proves that route with a hello-world: it builds the binary, checks it's aarch64 and static, and runs it under qemu.

Checked 2026-10-23.

| Setup | Versions on docs-t1 | Route to linux-arm64 | Smoke | |---|---|---|---| | Go, Go + Rastrillo | Go 1.26.10 | CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build | ok, static | | Rust | rustc 1.99.1, cargo-zigbuild 0.24 | cargo zigbuild --target aarch64-unknown-linux-musl (zig is the linker) | ok, static | | Zig | Zig 0.17.0 | -target aarch64-linux-musl | ok, static | | Swift | Swift 6.2 + Static Linux SDK | swift build --swift-sdk aarch64-swift-linux-musl | ok, static | | OCaml | opam 2.6.1, OCaml 5.3.0 (switch bakeoff) | Build inside the arm64 root: OCaml 5.3.0, ocamlfind and opam 2.3 for arm64, link with -ccopt -static | ok, static | | Haskell | GHC 9.10.3, cabal 3.16 (ghcup) | Build inside the arm64 root: GHC 9.6.6 and cabal 3.10 for arm64, link with -static -optl-static -optl-pthread | ok, static | | Nim | Nim 2.2.12 | nim c --cpu:arm64 --os:linux --cc:clang with --clang.exe and --clang.linkerexe set to scripts/zigcc-aarch64-musl (zig cc, musl) and --passL:-static | ok, static | | Spinel | spinel abf54280 (tep's pin), tep, spinelkit, Ruby 4.0.9 + prism (pixi) | Either build Spinel inside the arm64 root and compile with --cc="cc -static", or follow lpay's zig cross-build (paulca/lpay spinel/BUILD-arm64.md) | ok, static (arm64 root route) |

The arm64 root

scripts/arm64.sh <command> runs a command in a Debian 13 arm64 root filesystem (~/.local/share/bakeoff-toolchains/arm64root) through proot and qemu-user. It needs no root access and no binfmt. The repo, $TMPDIR and the toolchains directory are visible inside at the same paths. Everything in it runs emulated, so builds are several times slower than native. Install extra Debian packages with scripts/arm64.sh apt-get install -y <pkg>.

The root is shared. Other builders use it at the same time. If apt or dpkg reports a lock, wait a minute and retry. Install what you need, but never remove or downgrade packages others may rely on, and keep your build output and caches under your own app directory (for example apps/<slug>/.cache/), not in the root's /root or /tmp.

To run any arm64 binary on docs-t1: qemu-aarch64-static -L ~/.local/share/bakeoff-toolchains/arm64root <binary>.

Notes for builders

• OCaml and Haskell: the x86 compiler versions differ from the arm64 root's (OCaml 5.3.0 in both; GHC 9.10.3 on x86 but 9.6.6 in the root). Choose library versions that build with the arm64 root's compiler, or install a matching one inside the root (ghcup and opam both work there, emulated).
• Static glibc (OCaml, Haskell, Spinel via the arm64 root) warns about getaddrinfo and dlopen. That's fine for an app that doesn't resolve hostnames itself.
• Mojo was removed from the bakeoff (Paul's call, 2026-10-24). Mojo 1.2.0 can't make a single-file binary: every executable needs libKGENCompilerRTShared.so (plus libstdc++, libMSupportGlobals.so and libAsyncRTRuntimeGlobals.so), and no static runtime ships. In 2023 its authors described fully standalone binaries (news.ycombinator.com/item?id=35797485); that no longer holds. The finished app is kept on the app/mojo branch, and the platform Idea is amadan.net/carlos/platform discussion 360.
• Fallback: if a route above fails for a real app, the builder writes BLOCKED needs-arm64-host, and the orchestrator arranges a native arm64 machine.