Known Issues

Platform

• Linux-first. Unit tests run anywhere, but live engine integration, the FSI MCP flow, and every container recipe target Linux. The Hub GUI has not been tested on Windows or macOS.
• SkiaSharp GPU backend segfaults in the dev-container environment. FSBar.Viz uses a raster SKSurface + GL texture upload instead — see src/FSBar.Viz/Viewer.fs.
• Graphical engine runs windowed only. EngineLauncher forces Fullscreen=0 in per-session springsettings.cfg.

Hub

• Pause state can drift if the user types /pause in BAR's native UI — the Hub's IsPaused flag won't reconcile. Click the Viewer-tab pause button twice to recover. (Tracked in feature 038 notes.)
• Admin channel requires a fresh launch. The UDP autohost socket binds at SessionManager.Launch, not at Hub startup. Controls render dimmed and show an inline reason whenever SessionManager.AdminStatus <> Some Attached.
• Headless renderer is raster-only (same GPU caveat as above). Suitable for preview and streaming, but not high-FPS.

Trainer / tests

• *GrpcLogStream tests are order-sensitive.* TruncatedContent can corrupt server-side buffer state; run LogStreamTests individually rather than as a suite.
• Live tests need a real BAR install. ./tests/check-prerequisites.sh diagnoses missing pieces. Missing engines cause the whole live suite to skip, not fail.
• Map-cache codeVersion mismatch is a hard abort in the trainer warmup — by design. Regenerate via bots/trainer/map-cache/refresh-all.sh after bumping the version.

FSI REPL

• DLL references are locked once loaded. After a rebuild, restart FSI (restart_fsi MCP tool) or the MCP server.
• Native libraries must be dlopen'd before first SkiaSharp/GLFW use — see the preamble in scripts/examples/Repl.fsx.

Proto regeneration

• No prebuilt protoc-gen-fsgrpc. Generated files are committed, so dotnet build works out of the box. Regeneration requires installing the patched plugin via the helper in the sibling fsGRPCSkills repo.

Scope gaps

• No Windows or macOS CI matrix.
• Hub settings schema bumps are one-way (additive fields only); downgrading to an older Hub after a schema bump is not supported.
• buf breaking is run manually rather than on every push — wire contract parity relies on reviewer discipline.