Module discovery 

Working out where the repositories are, without being told.

devp init <path> has always registered a whole tree at once, but somebody has to know which tree to name. That is a fine thing to ask of a person setting their own machine up and a bad thing to ask of an assistant driving the tool on their behalf: an agent that has to guess ~/Code guesses wrong on the machine that keeps its work on D:\, and the repositories it never found are the ones that go on wasting disk.

So the roots are derived rather than guessed, from two sources that cost nothing:

1. The neighbourhood. People keep repositories next to each other. The parent of every registered repository is therefore a place where more of them probably live, and rescanning those parents is how registering one project ends up finding the rest of the workspace around it. This is the source that works on any layout, including drives and directory names no list could have anticipated.
2. The working directory. Bare devp init already scans ., so the workspace the command was run from is evidence that costs nothing in surprise — and it is the only evidence there is on a cold start where the code lives on a second drive.
3. The conventions. A machine with an empty registry has no neighbourhood yet, so constants::CODE_ROOT_NAMES is probed by name under the home directory. This is only ever the bootstrap: one registered repository anywhere makes source 1 better than this one will ever be.

Discovery registers. It does not delete, and nothing here shortens the distance between “registered” and “pruned”: a discovered repository still has to go idle, still has to have every candidate directory proved recoverable by a lockfile, and still has to clear all seven safety invariants before anything is removed. That is what makes registering by itself a safe thing to do — the worst outcome of a wrong guess is a row in devp status.

Structs

Discovery

What one discovery pass found.

Functions

candidate_roots

Every root worth walking, with the ones contained in another root removed.

discover

Look for repositories this registry does not know about.

discover_in

The body of discover, with the roots supplied rather than derived.

neighbourhood_roots

The parent directory of every registered repository, where that parent is deep enough to be a workspace rather than a home directory or a drive root.