nordisk/nornir

🚦 Viz pre-flight checks

What: right after the launch splash, nornir viz runs a handful of cheap capability probes and, if any fail, raises a centered popup. It turns the silent, downstream "scan failed: read …/Cargo.lock" class of error into an up-front, actionable prompt — and offers to fix the fixable ones.

Design

• Code: src/viz/preflight.rs (Preflight, Check), drawn from UrdrThreadsApp::update after draw_nornir_overlay and only once started_at.elapsed() >= SPLASH_DURATION_SECS, so it appears after the logo.
• A Check = { name, ok, detail, why, fixable, instructions }.
• LAW #6: Preflight::state_json() is folded into the viz dump under preflight — a test/agent sees the same checks the user sees.

Checks today

The one sanctioned shell-out

nornir is otherwise 100% Rust / no-shell. The only exception (Rickard, 2026-06-13) is the rustup installer, run from the Install rustup for me button — the official curl … | sh -s -- -y --profile minimal one-liner, in a background thread, gated behind an explicit click. We never install anything unasked. When it finishes the checks re-probe so a now-present cargo flips green (restart the shell/service so it's on PATH).

MCP-usage warning

If telemetry is loaded and 0 MCP calls are recorded, no agent has used nornir's 56 tools — so the operator probably hasn't wired the server into their Claude agent. The popup shows the exact claude mcp add command, built from this client's live connection (server endpoint + token — never a hardcoded secret), with a 📋 copy button. It does not pin NORNIR_WORKSPACE: the MCP exposes every workspace (see mcp-from-claude-code.md).

Clipboard

egui (which facett builds on) makes label text selectable and Ctrl+C / Ctrl+V work in any text field, popups included; the command block also has an explicit 📋 Copy button (one click, ctx.copy_text).

Why it matters (the bug it would have caught)

The server's nornir service user had no cargo on PATH, and library crates gitignore Cargo.lock, so Mimir.SecurityScan failed with a cryptic read …/Cargo.lock Internal. A pre-flight check states the real problem ("rust toolchain: cargo not found") and offers the fix, instead of letting it surface as a confusing scan error three clicks later.