vixen

vixen (vx) is a build engine for Rust with correct caching.

Quick Links

• Specification - Full specification document
• GitHub

Overview

vixen builds single-crate Rust projects using content-addressed storage and incremental computation. If inputs haven't changed, the second build is instant — zero compiler invocations.

vx build           # debug build
vx build --release # release build
vx clean           # remove .vx/ directory

Architecture

vixen uses a daemon-based multi-process architecture:

• vx — Thin CLI client. Connects to the daemon via roam RPC over a Unix socket.
• vxd — The daemon. Orchestrates builds using picante incremental queries. Parses manifests, constructs action graphs, executes actions.
• vx-runner — Remote compilation worker. Executes compile and link actions in isolated environments using CAS.
• vx-store — Content-addressable storage. Stores toolchains, sources, and build artifacts as blake3-hashed blobs.

Key Properties

• Correct caching — Cache keys are computed from the full set of inputs (source content, compiler flags, toolchain version). Changed inputs always trigger a rebuild; unchanged inputs never do.
• Hermetic toolchains — Rust and Zig toolchains are downloaded and stored in the global CAS. No system dependencies beyond a linker.
• Content-addressed storage — All artifacts are identified by their blake3 hash. Enables deduplication and integrity verification.
• Incremental computation — Uses picante for dependency tracking and single-flight memoization. Only affected queries re-run on changes.

Multi-Language Support

vixen supports C/C++ compilation via hermetic Zig toolchains, configured through vx.styx project manifests:

project {
    name hello
    lang c
}
bins ({
    name hello
    sources main.c
})

Current Scope (v0)

vixen deliberately limits scope in v0 to get the foundations right:

• Single-crate Rust projects (no workspaces)
• No external dependencies, features, build scripts, or proc macros
• No tests, benches, or examples
• Single binary target
• C/C++ via vx.styx manifests (pure C MVP)