(sigil cli serve)

Strip every leading "/" so a request path is always treated as relative to the served root (an absolute second arg would otherwise make path-join ignore the root entirely).

Resolve a request path to a readable file under root, or #f. Directories resolve to their index.html. The normalized target must stay within root (path-normalize collapses ".." so traversal is rejected).

Build the response for a resolved file. Compression is delegated to the shared (sigil http) helper http-response-gzip, which negotiates against the request's Accept-Encoding and only compresses worthwhile types.

Build a handler that serves static files from root.

Verify we can actually bind host:port, exception-free.

http-server-start does raise when tcp-listen fails, but that raise is not survivable in a release binary: sigil serve on an occupied port printed "serving <dir>", served nothing, and exited 0. A guard that relies on raise propagating is worthless in exactly the binary where propagation is broken, so this is a plain conditional plus a plain exit — the same reasoning as the fail-loud gate in build-cmds.sgl.

The probe socket is closed immediately and http-serve binds for real a moment later. That leaves a small window in which another process could take the port, which is fine: the point is to convert the overwhelmingly common case (something is already listening) from a silent success into a loud failure, not to provide an atomicity guarantee the OS does not offer here.

Serve root over HTTP on host:port. Blocks until interrupted.

Order matters: every claim printed here is printed only AFTER the thing it claims has been verified. root is echoed as an absolute path because it is resolved relative to the current directory, and a stale cwd silently serving the wrong tree (404ing everything) was its own papercut.