gig-line/Docs/toolchain.md

# Toolchain

Pinned versions for this project. Record the exact build string a tool reports, not just the version family, and re-record it after every upgrade. The most common cause of scale, material, and import mismatches is silently mixing two versions of the same tool.

Audited 2026-11-06, updated 2026-11-07 on the development workstation.

**State:** initial setup is complete. Every pinned tool below has been exercised on real work — the engine compiled game code and packaged a build, Blender/MPFB/Blosm produced committed assets, and QGIS's PROJ produced the project origin. The demo level (`/Game/Hollywood/DemoMap`) and packaged build exercise the engine path end to end; the only unexercised path is a fresh checkout, tracked as a `v0.1.0` release check.

## Pins

| Component | Pinned | Source | Status |
| --- | --- | --- | --- |
| Bazzite | `45.20261105` (Kinoite, `bazzite-dx-nvidia`), kernel `7.2.15-ogc1.1.fc45` | `ujust update` / `rpm-ostree upgrade` | Booted and default. `44.20261026` retained as rollback. |
| NVIDIA driver | `615.78.08`, open kernel module | Bazzite image | Verified: desktop session renders through the RTX 5070 Ti; Vulkan GPU0 is the RTX 5070 Ti on driver `615.78.08`, conformance `1.4.3.3`. |
| Unreal Engine | `5.8.4` — CL 58902052, `++UE5+Release-5.8`, promoted build | Epic download | Fully extracted to `/run/media/system/DATA/Engines/UE_5.8.4` (73 GiB on disk). **Validated 2026-11-07:** headless `-NullRHI` smoke test and full editor GUI launch with Vulkan RHI on the RTX 5070 Ti (loader 1.4.350, `VULKAN_SM5`, map check 0 errors). Pin is final. The verified 5.2.0 archive stays as fallback. |
| Unreal Linux toolchain | system `clang 23.1.4` (Fedora 45) | `rpm-ostree` layer | This 5.8.4 build ships **no** bundled Linux clang (no `clang++` anywhere in the engine tree, verified 2026-11-07); UBT compiles game code with the system toolchain. **Accepted 2026-11-07:** game-module compile and link (`GigLineEditor`, `libUnrealEditor-GigLine.so`) and a packaged Development build. Game targets use `BuildSettingsVersion.V7` + `EngineIncludeOrderVersion.Latest` (`Source/GigLine.Target.cs`, `Source/GigLineEditor.Target.cs`) to share the installed editor's build environment. |
| Blender | `5.2.0` LTS (build 2026-07-14) | Flatpak `org.blender.Blender` | Installed. Run headless from the app tree with `LD_LIBRARY_PATH` + `BLENDER_USER_SCRIPTS`; `flatpak run` is unavailable to the agent shell. |
| MPFB | `2.0.18` (extension `bl_ext.blender_org.mpfb`, `blender_version_min 4.2.0`) | Blender extensions platform | Installed. **Fully verified 2026-11-07:** generates a default human (19 158 verts, UVs), standard 137-bone rig with weights, and a baked 1024² skin; the character imports into Unreal as a `SkeletalMesh` with Skeleton, Material, and Texture. Headless runs must set `XDG_CONFIG_HOME=$HOME/.var/app/org.blender.Blender/config` or the extension is not discovered (`Art/blender/README.md`). |
| Blosm | `2.7.28` (legacy add-on, `bl_info.blender = (4, 5, 0)`, manifest min 4.2) | blosm.com | Installed and importing on Blender 5.2 in `3Dsimple` mode. Two headless workarounds are required; see `Art/blender/README.md`. Paid material asset pack lives in `~/Downloads/blosm-assets/` and is not committed. |
| QGIS | `4.2.3`, Flatpak `stable`, runtime `org.kde.Platform 6.11`; bundled PROJ `9.9.0` | flathub | Installed 2026-11-06. Stale `lts` branch (`3.28.9`, EOL Qt5 runtime) uninstalled 2026-11-07; only `stable` remains. |
| Git | `2.56.0` | Bazzite image | Installed. |
| Git LFS | `3.7.1` | `rpm-ostree` layer | Installed; `git lfs install` run, lfs filter active. |
| Host build tools | `clang 23.1.4`, `cmake 4.3.0`, `ninja 1.13.2` | `rpm-ostree` layer | Installed. These are host tools, not the engine toolchain. |
| distrobox | `1.8.2.5` | Bazzite image | Installed. |
| Python (tooling) | `3.14.8` system | Bazzite image | Installed. Use a venv for geo/tool scripts. |
| ffmpeg | `8.1.3` | Bazzite image | Installed. |

Unreal Engine 5.9 is in preview and Unreal Engine 6 has been announced as of November 2026. Neither is a pin candidate for `0.x`. One engine family per milestone; a family change is a breaking change and belongs in `CHANGELOG.md`.

## Agent skills

| Item | Value |
| --- | --- |
| Package | blender-skills `1.3.0`, upstream commit `8f778d2`, MIT |
| Source | <https://github.com/arjun988/blender-skills> |
| Location | Local only, common root: `~/.pi/agent/skills/` (93 packs, `references/`, `LICENSE`) — not distributed with the repository |
| Project-specific | `.agents/skills/blender-skills/blender-director/` (gitignored, not committed) |
| Installed | 2026-11-06, copied from a local checkout of `.claude/skills/` without edits; flattened to the common root on 2026-11-10 |
| UE skills | `quodsoler/unreal-engine-skills` `f3742d7`, MIT — 31 packs at `.agents/skills/ue-*/` (gitignored), target UE 5.8 C++ |
| C++ skill | `DiamonDinoia/skill-cpp` `f2617fb`, MIT — `cpp` router at `.agents/skills/cpp/` (gitignored) |

All skill packs — Blender, Unreal and C++ — are agent instructions, not code that runs in a build, and **none are committed**: `/.agents/skills/` is gitignored and the Blender packs live in the common `~/.pi/agent/skills/` root. Four of the Blender packs assume a **Blender MCP server**; this project drives Blender headlessly through `bpy` (`Tools/*.py`) instead, so MCP is optional and nothing depends on it.

To update a pack:

- **Blender** — copy `.claude/skills/` from a newer `arjun988/blender-skills` checkout over `~/.pi/agent/skills/`, then record the version and commit in the table above.
- **Unreal Engine** — re-install the `quodsoler/unreal-engine-skills` git source at the new commit (`pi install <source-url>@<commit>`); the 31 packs land under `.agents/skills/ue-*/`. Record the commit in `skills.manifest.json` and the table.
- **C++** — re-install the `DiamonDinoia/skill-cpp` git source at the new commit; the router lands at `.agents/skills/cpp/`. Record the commit in `skills.manifest.json` and the table.

`skills.manifest.json` (in `.agents/skills/`) is the install record — the git sources, commits and layout — and is the thing to keep in step with the table. Skills are read on demand, so the harness catalog may need a reload before they appear as first-class entries.

## Pin rules

- One engine build per release. Record the launcher or source build, the patch version, and the build date in this file and in the release entry.
- Blender stays on an LTS family (`5.2`). Every add-on version used for a shipped asset is recorded here.
- Upgrading a pinned tool mid-milestone requires re-running the scale test and the Blender→Unreal import check before further asset work.
- Never install a tool from an unverified source. Record the download origin next to the version.

## Open compatibility risks

1. **Blosm on Blender 5.2 — worked around, not resolved.** `3Dsimple` import works headless (see the blockout). Two headless-only defects are patched around in the script rather than in the add-on: an asset-directory check that fires before `mode` is honoured, and a background-mode import path that uses a broken relative import when the default level table is empty. `3Drealistic` mode has not been exercised; it loads the paid material pack and previously failed inside the realistic renderer setup. If realistic materials are wanted, test that mode separately before depending on it.
2. **MPFB 2.0.18 on Blender 5.2.** The extension declares Blender >= 4.2 but predates 5.x. Generation verified 2026-11-07: `mpfb.create_human` works headless once `XDG_CONFIG_HOME` points at the Flatpak config tree. Remaining acceptance test is the `0.1.0` requirement to export one MPFB character with baked materials and a deform skeleton and import it into Unreal.
3. **QGIS 4.x recipes.** Only `stable` (4.2.3) is installed now; the old `lts` was removed 2026-11-07. QGIS 4.x uses Qt6, so any processing recipe copied from a 3.x tutorial needs re-checking before it is trusted.
4. **Driver and Vulkan validation on Bazzite.** Not an officially supported Unreal distribution. The engine install itself is proven (full init headlessly); only the Vulkan RHI on the RTX 5070 Ti is unproven, and one desktop-terminal run settles it.