# Dev Setup > Setting up a Capsem dev environment from scratch. Use when onboarding, provisioning a machine, or troubleshooting environment and container-runtime issues. - Skill: `google/dev-setup` (Agent Skill) - Install (CLI): `npx skillmds@latest add google/dev-setup` - Raw SKILL.md: https://api.skillmd.com/api/skills/google/dev-setup/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: Google (https://skillmd.com/u/google) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/google/dev-setup --- # Developer Setup ## Prerequisites - **Linux**: supported Debian/Ubuntu or dnf-based host, x86_64/arm64, sudo/root for initial packages, and `/dev/kvm` plus `/dev/vhost-vsock` for VM execution and guest communication - **macOS 13+** (Ventura or later) -- required for Virtualization.framework - **Apple Silicon** (arm64) -- primary macOS target. Intel Macs are not supported for VM features. - **Docker** (native on Linux, Colima on macOS) -- needed for `just _build-assets` (kernel + rootfs builds) - **Tart + sshpass (macOS)** -- needed for the clean-macOS package install owned by `just test` ## Required tools Run `just doctor` to check all of these: | Tool | Purpose | Install | |------|---------|---------| | Rust (stable) | Host + guest binaries | `rustup` | | just | Task runner | `cargo install just` | | pnpm | Frontend package manager | `npm i -g pnpm` | | Node.js 24+ | Frontend build | `nvm` or `brew install node` | | uv | Python package manager | `curl -LsSf https://astral.sh/uv/install.sh \| sh` | | Docker (via Colima on macOS) | VM image builds | `brew install colima docker` (macOS) or `sudo apt install docker.io` (Linux) | | Docker BuildKit (buildx) | Cross-arch container builds | `brew install docker-buildx` (macOS); bootstrap selects `docker-buildx` from Ubuntu/Debian archives or the discovered `docker-buildx-plugin` fallback | | Bubblewrap (Linux) | Kernel-enforced loopback-only host gate | `sudo apt install bubblewrap` (bootstrap-owned) | | cpio | Initrd unpack/repack | system on macOS; `sudo apt install cpio` or `sudo dnf install cpio` on Linux (bootstrap-owned) | | Tart + sshpass (macOS) | Disposable clean-Mac package install gate | `brew trust --formula cirruslabs/cli/softnet && brew install cirruslabs/cli/tart cirruslabs/cli/sshpass` | Rust targets (auto-installed by `just doctor fix`): - `aarch64-unknown-linux-musl` -- guest binaries (arm64) - `x86_64-unknown-linux-musl` -- guest binaries (x86_64) Cargo tools (auto-installed by `just doctor fix`): - `cargo-nextest` -- native Rust test runner - `cargo-llvm-cov` -- coverage - `cargo-audit` -- vulnerability scanner - `cargo-tauri` -- Tauri CLI - `cargo-sbom` -- Rust SBOM generation - `b3sum` -- BLAKE3 checksums ## Container runtime setup On macOS, Docker runs inside a Colima VM. The default memory allocation may be too small -- the rootfs build runs apt installs, npm installs, and curl-based CLI installers concurrently, which can OOM-kill the build (exit code 137). **Minimum**: 12GB RAM. **Recommended**: 16GB RAM, 8 CPUs (Tauri's GTK/webkit2gtk dep chain pushes the install-test build past 8GB on cold caches; 12GB is the floor that doesn't OOM). ### Colima (macOS) ```bash # First-time setup brew install colima docker colima start --vm-type vz --vz-rosetta --memory 16 --cpu 8 # Restart with new resources colima stop colima start --vm-type vz --vz-rosetta --memory 16 --cpu 8 # Verify docker info | grep -E 'Total Memory|CPUs' ``` ### Colima recovery discipline If Docker-dependent recipes fail on macOS, do not report Docker/Colima as unavailable until you have checked for the common half-running Colima state. The signature is: - `colima list` says the profile is `Running` - `docker version` / `docker info` cannot connect to `~/.colima/default/docker.sock` - `colima ssh -- docker ps` fails with `kex_exchange_identification`, `Connection reset by peer`, or `colima status` reports `error retrieving current runtime: empty value` First recovery attempt: ```bash colima stop colima start docker version ``` If the profile needs its expected resources restored, start with the explicit Capsem defaults instead: ```bash colima stop colima start --vm-type vz --vz-rosetta --memory 16 --cpu 8 docker version ``` Only after that restart fails should you treat Colima as a real environment blocker. Record the exact failed command and the Docker/Colima output. ### Linux Docker runs natively on Linux -- no Colima or memory tuning needed. Canonical bootstrap installs the native build libraries, Docker/Buildx, and Bubblewrap; installs the distro's QEMU user/binfmt package and proves the fix-binary registration Docker needs for the other architecture; enables the daemon; loads KVM and vhost-vsock; and provisions both device nodes for repeated VM lifecycles in the current shell. KVM uses the same durable mode as Linux release CI because systemd-logind can remove a named ACL after the first VM exits. vhost-vsock remains group-owned with a narrow current-user ACL. Do not hand-provision binfmt or either device, and do not weaken the separate macOS VZ/Seatbelt path; rerun the checked-in bootstrap so distro registration and udev rules remain the authority. ```bash ./bootstrap.sh --yes ``` `just doctor` checks these resources automatically and fails if below minimum. On Linux bootstrap and hosted CI run the checked-in Bubblewrap proof: only `lo`, usable loopback/devices, and no direct egress. An ephemeral GitHub Ubuntu runner may lift only the exact AppArmor user-namespace switch responsible for `RTM_NEWADDR`, after which the complete proof must pass again. Local bootstrap never applies that hosted repair. When doctor is already inside a gate, it verifies that only `lo` is visible instead of attempting a nested namespace. ## First-time setup ```bash # 1. Clone and enter git clone && cd capsem # 2. Bootstrap (interactive: prompts [Y/n] before each install; --yes for CI) ./bootstrap.sh # ./bootstrap.sh --yes # non-interactive # 3. Boot the VM to verify everything works just exec "echo hello from capsem" ``` `bootstrap.sh` is the deliberately public **repo-root** bootstrap entrypoint. It runs `just _build-assets` as part of doctor's auto-fix, so step 3 just confirms the VM boots. ### What bootstrap installs Three phases. Default at every prompt is **Yes** (Enter accepts; type `n` to decline). `--yes` and non-tty input both auto-accept. | Phase | Tool | Channel | |-------|------|---------| | 1 (hard prereqs) | `bash`, `git`, `curl` | system package manager (you install) | | 1 | `rustup` (stable, minimal profile) | `sh.rustup.rs` | | 1 | `just` | `just.systems` -> `~/.local/bin` | | 2 | `uv` | `astral.sh/uv` -> `~/.local/bin` | | 2 | Python lock metadata + deps | `uv lock --project build_system --locked` then `uv sync --project build_system --frozen` | | 2 | Rust workspace deps | `cargo fetch --locked` before sandboxed qualification | | 2 (Linux) | native compiler/Tauri libs, `cpio`, Docker/Buildx, Bubblewrap | apt or dnf | | 2 (Linux) | configured Node major + pnpm 10 | SHA256-verified official Node archive + npm | | 2 (Linux) | Docker/KVM/vhost-vsock current-session access | groups + checked-in udev policy and narrow socket/vhost ACL | | 2 (macOS) | `flock`, `pnpm` | `brew` | | 2 (macOS) | `tart`, `sshpass` | `brew` | | 2 (macOS) | `colima`, `docker`, `docker-buildx` | `brew` (+ symlink into `~/.docker/cli-plugins`) | | 2 (macOS) | Colima VM | `colima start --vm-type vz --vz-rosetta --memory 16 --cpu 8` | | 2 | Frontend, docs, site, and release-site deps | config-driven `capsem-gate install-node` with frozen lockfiles | | 3 | Doctor `--fix` | `build_system/scripts/doctor/doctor-common.sh --fix` -- Rust targets, exact config-owned Cargo tools (`cargo-nextest`, `cargo-llvm-cov`, `cargo-audit`, `b3sum`, `cargo-tauri`, `cargo-sbom`), build VM assets, pack initrd | The VM asset rail materializes its digest-pinned OBOM tools inside its own architecture-matched helper; do not install a parallel global cdxgen. ### Kernel version Kernel selection is part of the profile-derived image build, not a standalone developer setting. The build backend reads the exact kernel release and SHA-256 from the checked-in build contract, then verifies the source archive before extraction while building profile assets through `capsem-admin`/`just`. Do not add a parallel kernel setting or a mutable latest-release lookup. Or step by step: ```bash just doctor # Check tools (colored output, structured recap) just doctor fix # Auto-fix missing targets, cargo tools, config files just _build-assets # Build kernel + rootfs (~10 min) just exec "echo hi" # Verify VM boots ``` If step 4 prints "hello from capsem" and exits cleanly, you're set. ## Daily workflow ```bash just shell # Build + boot VM interactively (~10s) just exec "CMD" # Build + boot + run command + exit just fast-test # Incomplete source feedback before expensive work just focus-test functional # Rerun one affected functional owner just test # Optional reusable whole-system proof when warranted just dev ui # Frontend dev server (mock mode, no VM) just dev # Full Tauri app with hot-reload ``` See `/dev-just` for the complete recipe reference. ## Credentials Do not create `~/.capsem/user.toml`. Credentials are captured and replayed by the credential broker plugin through profile/corp policy. Hermetic tests use the local mock server and Ironbank fixtures; real OAuth/API-key manual runs are debug evidence, not release proof. Do not add setup-time admin or guest config roots. Runtime behavior is profile/corp-owned; settings are UI/application preferences only. Generated settings UI metadata may render controls, but it is not a product config authority. ## Claude Code permissions To avoid repeated permission prompts when using `just` and `capsem` commands, add these to your Claude Code settings. Run `/update-config` or edit `.claude/settings.local.json`: ```json { "permissions": { "allow": [ "Bash(just *)", "Bash(uv run --project build_system --frozen *)", "Bash(cargo *)", "Bash(pnpm *)", "Bash(cd web/app && pnpm *)", "Bash(npx *)", "Bash(python3 build_system/scripts/*)", "Bash(rustup *)" ] } } ``` This allows: - `just *` -- all recipes (run, test, build-assets, query-session, list-sessions, doctor, etc.) - `uv run --project build_system --frozen *` -- capsem-builder CLI and Python scripts - `cargo *` -- Rust builds, tests, checks - `pnpm *` -- frontend package management and builds - `npx *` -- skills CLI and other npx tools - `python3 build_system/scripts/*` -- project build and diagnostic boundaries - `rustup *` -- cache/target/component management ## Codesigning The app binary must be codesigned with `com.apple.security.virtualization` entitlement or Virtualization.framework calls crash. The justfile handles this automatically via `_sign` recipe. **Prerequisites** (macOS only): - Xcode Command Line Tools: `xcode-select --install` - `build_system/packaging/macos/entitlements.plist` must exist (checked into git) **Verification**: `just doctor` includes a signing test that compiles a tiny binary, signs it with the entitlements, and verifies the operation succeeds. Run `just doctor` after initial setup to confirm signing works. **Linux developers**: codesign is not available and not needed on Linux. VM features use the KVM backend when `/dev/kvm` and `/dev/vhost-vsock` are available. Use `just test` for the same artifact-recording performance suite as macOS. ## Troubleshooting ### `just exec` fails with codesign error - Run `just doctor` -- it will diagnose the specific signing issue - Ensure Xcode CLTools are installed: `xcode-select --install` - Check entitlements file exists: `cat build_system/packaging/macos/entitlements.plist` - Try manual sign: `codesign --sign - --entitlements build_system/packaging/macos/entitlements.plist --force cache/target/cargo/debug/capsem` - Check SIP status: `csrutil status` ### `just doctor` fails Run `just doctor fix` to auto-fix all fixable issues. Fixes run in dependency order (rustup targets before cargo tools before build-assets before pack-initrd). Non-fixable issues show install hints. ### `just _build-assets` or `just _gate-install` fails with exit code 137 (or 143 mid-cargo-build) The container runtime VM ran out of memory. Bump Colima to at least 12GB (16GB recommended): - Colima: `colima stop && colima start --vm-type vz --vz-rosetta --memory 16 --cpu 8` - Linux: Docker runs natively, no memory tuning needed ### `just _build-assets` fails with "Release file not valid yet" The container VM's clock has drifted. The builder uses `Acquire::Check-Valid-Until=false` to work around this, but if you see this error on an old builder version: - Colima: `colima stop && colima start --vm-type vz --vz-rosetta --memory 16 --cpu 8` (resets clock) - Docker Desktop: restart Docker Desktop ### `just _build-assets` fails (other) - Check Docker is running: `docker info` - Check the profile contract is valid: `capsem-admin profile check config/profiles/code/profile.toml --config-root config` - On first run, Docker image pulls can be slow ### `just exec` fails with "assets not found" Run `just _build-assets` first. Assets are gitignored and must be built locally. ### `cargo run` or `cargo test` crashes with signing error - `.cargo/config.toml` must exist and be tracked in git -- it configures the custom runner (`build_system/packaging/macos/run_signed.sh`) that signs binaries with Virtualization.framework entitlements before execution - If missing: `git checkout .cargo/config.toml` - The justfile `_sign` recipe signs separately, so `just exec` works even without the cargo runner -- but direct `cargo run`/`cargo test` and IDE integrations will crash - **Lesson:** bare `.gitignore` patterns (no `/` prefix) match at any depth. Always anchor with `/` when you mean root-only (e.g., `/config.toml` not `config.toml`), or you risk silently ignoring files in subdirectories like `.cargo/` ### Cross-compile errors - Check `.cargo/config.toml` has linker config for musl targets - Run `rustup target add aarch64-unknown-linux-musl x86_64-unknown-linux-musl` - Platform-specific type issues: use `as _` for libc calls (see `/dev-rust-patterns`) ### Disk full / Colima eating all disk space Docker builds accumulate images, BuildKit data, and stopped containers inside the Colima VM. Inspect and reclaim them through the typed cache controller so active images, foreign resources, retention pins, and every applied deletion remain visible in one inventory and journal: ```bash just cache stats just cache prune docker # exact preview; no mutation just cache prune docker --apply --reason "Colima cache recovery" ``` Do not bypass this with broad `docker system/image/builder prune` commands: they cannot distinguish active Capsem reuse from disposable state and leave no controller journal. The runtime adapter runs the configured host-side trim after an applied Colima reclamation. `just cache stats` reports repository and native-runtime state together; use `--offline` when Docker or Tart is intentionally unavailable. Read `/dev-cache` before changing cache ownership, limits, or cleanup behavior. ### Docker credential helper error (`docker-credential-osxkeychain not found`) When Colima is installed standalone (without Docker Desktop), `~/.docker/config.json` may reference a credential helper that doesn't exist. The symptom is `docker run` failing to pull images with `exec: "docker-credential-osxkeychain": executable file not found`. Fix: set `credsStore` to empty string in `~/.docker/config.json`: ```json { "credsStore": "" } ``` `just doctor` checks for this under "Container Runtime" and will flag the mismatch. ### VM boot hangs - Check codesigning: `codesign -dvv cache/target/cargo/debug/capsem 2>&1 | grep entitlements` - Check assets exist: `ls cache/target/assets/arm64/vmlinuz cache/target/assets/arm64/rootfs.erofs` - Check kernel architecture matches host: wrong-arch kernel causes silent hang. `VmConfig::build()` now rejects mismatched kernels at config time. - Try with debug logs: `RUST_LOG=capsem=debug just exec` ## Doctor architecture The doctor system is three bash scripts: ``` build_system/scripts/doctor/ doctor-common.sh # Entry point, cross-platform checks, fix registry, recap doctor-macos.sh # macOS: Tart, Colima, Rosetta, codesigning, brew hints doctor-linux.sh # Linux: KVM, apt/dnf hints ``` `just doctor` calls `doctor-common.sh`. `just doctor fix` calls `doctor-common.sh --fix`. ### Fix registry All fixable issues use an **ordered fix registry** defined at the top of `doctor-common.sh`. Each entry has an ID, command, and description. Checks call `fixable