# kern 1.0.0-rc2

> Static file serving and safe long-lived state. Reproducible across two machines.

Source: https://kern-lang.eu/releases/1.0.0-rc2

Static file serving and safe long-lived state

July 14, 2026

## Release notes

## v1.0.0-rc2, static file serving and safe long-lived state

`http_static(prefix, dir)` now actually serves files, over both plain HTTP and HTTPS (it was a no-op that recorded the mount but never read it). Content type is set by extension, `index.html` is served for directories, requests are `GET`/`HEAD` only, and a strict path-traversal guard rejects any `..` with a `403` before a file is ever opened (verified it will not serve `/etc/passwd`); the TLS path was refactored around a write sink so the same implementation serves plaintext and TLS sockets correctly. `persist(s)` is the epoch-GC escape hatch: under request-scoped GC (`KERN_HTTP_EPOCH_GC`) every object allocated during an HTTP request is reclaimed at request end, so a request-derived key stored into a long-lived global map (a rate-limiter's client-IP table, a cache) would dangle; `persist` copies the bytes onto the permanent heap so they survive, implemented as a thread-local allocator redirect that leaves epoch and collection semantics untouched.

## v1.0.0-rc2, adopter tooling: version pinning and a Docker-independence attestation

Two adopter-requested tools turn claims into checks. A one-line `.kern-version` file pins the toolchain: `kern build` / `run` / `check` compare it to the running compiler and print `warning: kern-version-mismatch` when a compiler upgrade or a stale binary drifts from what the project expects (warning-only, so it never breaks a build; CI that wants hard enforcement greps for the line). `kern audit-docker <file>` walks a program's full resolved import graph and reports whether it takes any Docker dependency (an import of `sys.docker`, which shells out to the docker CLI, or a `/var/run/docker.sock` reference): a clean program prints `audit-docker: PASS`, a Docker dependency is `FLAGGED` and the command exits non-zero so CI can gate on it. “Docker-free” becomes auditable: a Kern binary is native and links no Docker client.

[Read the announcement: kern v1.0.0-rc2, reproducible across two machines ](https://kern-lang.eu/blog/v100-rc2-release)