hive-elm

Elm build watching as a hive IAddon. It runs elm make --report=json, turns the compiler's report into values, and shouts each new failure on the hivemind, so a model working on an Elm project hears that the build broke without having to ask.

-- MODULE NOT FOUND -- src/Main.elm:7:8

You are trying to import a `Theme.Tokens` module:

7| import Theme.Tokens as Tokens
          ^^^^^^^^^^^^
I checked the "dependencies" and "source-directories" listed in your elm.json,
but I cannot find it! ...

Commands

The addon contributes the elm subdomain to the host's code tool.

Command	What it does
code elm check directory=<root>	Compile once and return the problems. Tells nobody.
code elm watch start directory=<root> parent=<agent-id>	Watch the sources. Shout each new failure and each recovery.
code elm watch status directory=<root>	Build state and the last 50 checks.
code elm watch stop directory=<root>	Stop the watcher.
code elm doctor directory=<root>	Which elm would run, whether it runs, and where a failure would go.

A failure is shouted once. Saving again without fixing it stays quiet; a different failure, or the same one after a clean build, is news again. A clean build is shouted only right after a failure.

How a failure reaches the model

The watcher shouts event type :build-failed (and :build-recovered) as agent elm:<directory name>. From there the host carries it two ways:

• Piggyback. The shout is appended to the next tool result of the reader it is addressed to, in the ---HIVEMIND--- block.
• sixth-sense (ss). On load the addon registers the sense class :sense/build-failed, with the detail fields build-tool, build-title, build-file, build-line and build-problems. sixth-sense then pushes the failure to an idle session instead of waiting for its next tool call.

Both address by parent. Pass parent=<your agent id> to watch start (or set it in hive-elm.edn) to hear the failures of the project you are working on. Without a parent, only coordinator readers do.

Neither hive-mcp nor hive-agent is a dependency: both are resolved when needed. Outside a host, check works and the watcher records failures in its log without delivering them.

Configuration

None is required. The entry module defaults to src/Main.elm, or .elm-land/src/Main.elm for an elm-land project; source directories come from elm.json; the compiler is node_modules/.bin/elm when the project pins one, else elm on PATH.

To override, put hive-elm.edn at the project root:

{:hive.elm/entries ["src/Main.elm" "src/Admin.elm"]
 :hive.elm/command ["npx" "--no-install" "elm"]
 :hive.elm/watch   {:poll-ms 500 :debounce-ms 300}
 :hive.elm/notify  {:parent-id "coordinator:1234"}}

The watcher type-checks with --output=/dev/null: it writes no artifact, so it does not race the project's own bundler (elm-land, vite) over an output file. It does share elm-stuff/ with it, as two elm make runs always do.

The compiler's report

Read off the compiler source (elm 0.19.3) and measured against 0.19.1:

• A failed build writes one line of JSON to stderr and exits 1. A clean build writes nothing and exits 0.
• {"type": "compile-errors", "errors": [{path, name, problems: [{title, region, message}]}]} for problems in modules. Paths are absolute; lines and columns are 1-based.
• {"type": "error", path, title, message} for everything else: a broken elm.json, a missing file, an import cycle, a dependency problem. path is "elm.json" or null.
• A message is a list of strings and styled spans {bold, underline, color, string}; hive-elm keeps the text and drops the styling.
• Flag errors and compiler crashes are plain text, not JSON. hive-elm keeps that text verbatim as a single BUILD FAILED problem.
• A module that imports a failing module reports nothing, and a syntax error is the only problem its module reports, so fixing one failure can reveal the next.

Development

clojure -M:test          # unit tests: stub ports, no elm needed
clojure -M:integration   # runs a real elm over a scratch project

Layout

Namespace	Stratum
hive-elm.schema	Value objects (malli)
hive-elm.ports	IElmCompiler, IBuildNotifier, IFileStamps, IClock
hive-elm.report, hive-elm.watch, hive-elm.manifest	Pure: parse, decide, resolve
hive-elm.watch.supervisor	Pipeline over the ports
hive-elm.compiler.process, hive-elm.stamps.fs, hive-elm.notify.*, hive-elm.boundary	Adapters and boundary
hive-elm.addon*	IAddon and the code elm commands