Dev Environment Setup & Verification

Step 1: Check required tools

Run these checks and install if missing:

• which wasm-pack — if not found: cargo install wasm-pack
• which maturin — if not found: pip install maturin
• which uv — should be available at /root/.local/bin/uv
• node --version — should be v22+
• cargo --version — should be available

Step 2: Check node_modules

If node_modules/ does not exist, run npm install.

Step 3: Check WASM build

If crates/megane-wasm/pkg/ does not exist, run npm run build:wasm. This step is REQUIRED before npm run dev or npm run build will work.

Step 4: Check Python environment

• Run uv sync --extra dev to ensure Python deps are installed
• If Python tests are needed, also run maturin develop --release to build the native extension

Step 5: Verify

• Run npm test to confirm TypeScript tests pass
• Run cargo test -p megane-core to confirm Rust tests pass

Common Failures

• "wasm-pack: command not found" → cargo install wasm-pack
• "maturin: command not found" → pip install maturin
• Vite dev server fails with missing WASM → run npm run build:wasm first
• Python import errors → run maturin develop --release
• Node module not found → run npm install

VSCode E2E hosts (code-server)

Only needed to run the vscode / widget-vscode Playwright projects. scripts/install-code-server.sh installs code-server + the Jupyter extensions + the megane VSIX. In a sandboxed / proxied environment the default installer downloads a binary from GitHub and gets HTTP 403; force the npm build path instead:

sudo apt-get install -y libkrb5-dev      # kerberos native build needs GSSAPI headers
MEGANE_CODE_SERVER_USE_NPM=1 bash scripts/install-code-server.sh

The npm route builds code-server into <repo>/.code-server (gitignored) and needs libkrb5-dev (else node-gyp fails on gssapi/gssapi.h) and rg on PATH (else @vscode/ripgrep's GitHub download fails). See the e2e-coverage skill for the full runbook and the MEGANE_CODE_SERVER_BIN invocation.