nucleic-windows/spikes/README.md

M1 spikes (docs/WINDOWS_PORT.md §13)

Programs that answer questions the port is currently guessing at. They are checked in and runnable on purpose: a spike whose answer nobody can reproduce six months later is a rumour.

They are deliberately not in windows/Nucleic.sln. The solution's broker contract tests must keep running on any machine against FakeWslc; these need the Microsoft.WSL.Containers preview NuGet and a real WSL stack, so they are built by path.

---

WslcApiDump — what does the wslc API actually look like?

The problem it solves. Items 5, 6 and 7 — the C# broker, the Swift wslc client, and the control plane — were all built against Microsoft's documentation, on machines with no WSL. NucleicBroker/Wslc/WslcFacade.cs is therefore a careful transcription that has never been compiled against the real assembly, and -p:UseWslc=true is the only thing standing between it and the build. Every line in it might be right. We have no idea which.

A typed spike cannot tell us: if Session.CreateOrOpen is really Session.Open, the spike fails to compile, which teaches us one name and stops. So this tool is written entirely in reflection. It cannot fail to build, and a single run prints the complete list of what is wrong.

cd windows/spikes/WslcApiDump
dotnet run                      # dump the API + check every facade assumption
dotnet run -- --probe           # + call the two read-only statics (service version, missing components)
dotnet run -- --session         # + create a real session and print its live property VALUES

It writes the full public object model to wslc-api-dump.txt (--out to relocate) and prints an ok / MISSING line per assumption, each with why that member matters and a nearest-name hint. It exits 0 even when assumptions fail — a mismatch is the product, not an error. Only a genuinely broken run (the assembly won't load) exits non-zero.

What to send back: the console output, and wslc-api-dump.txt if anything is MISSING.

Why --session earns its risk

--session creates a real wslc session named nucleic-spike under %LOCALAPPDATA%\Nucleic\spike\wslc and leaves it running. It exists for one question that type metadata cannot answer: where does the WSL-facing host gateway address come from? §5 makes gateway TCP the primary control-plane transport, WslcContainerEngine.ensureRunning returns that address to the Swift side, and control-bridge.js dials it. The facade guesses Session.HostGatewayAddress. Dumping the live values of every session property lets us recognise a gateway IP whatever it is called — and if nothing on the session looks like one, that is itself the finding, and §5's hvsocket fallback gets promoted from upside to dependency.

Leaving the session running is also the cheap version of a §2.3 question: broker supervision assumes wslc state is service-backed, so that a crashed nucleic-brokerd can reattach and re-enumerate rather than orphaning containers. If wslc session ls still shows nucleic-spike after this process exits, that assumption holds. Tear it down with wslc when you're done.

The three answers that change the design

Most mismatches are a one-line edit in WslcFacade.cs — that is exactly what the IWslc seam is for, and nothing above it should move. These three are different:

Finding	Consequence
No create-or-attach on Session	Broker-crash reattach (§2.3) has no mechanism; supervision needs redesigning before item 11.
No gateway address on a live Session	§5's primary transport loses its source; promote the AF_HYPERV/AF_VSOCK fallback and spike that instead.
No uid on ProcessSettings	Recoverable, and already planned for: exec wraps argv in setpriv/su agent -c. Interceptors and nash don't care about the numeric uid (§3.2).

---

Not yet written

• WslcSpike — the typed happy path: session → GHCR pull of naros-agent → container with an NTFS ContainerVolume → exec git status in the bind-mounted worktree → stdio round-trip → SIGTERM, plus the 9P latency numbers §15 wants (git status and npm install on a real repo, mounted vs. in-VM). Deliberately held back until WslcApiDump has run: written now, against guessed names, it would not compile, and fixing it blind is the mistake this whole approach exists to avoid.
• HvSocketSpike — M1 (b): AF_HYPERV host listener ↔ AF_VSOCK dial from inside a wslc container, plus gateway-TCP reachability and default-firewall behaviour in NAT and mirrored modes. Only worth building once a container can be started at all.