# Red Bear OS — Build & Boot Fix Summary

**Date**: 2026-05-03
**Oracle-reviewed**: Yes (3 rounds)

## Applied Fixes

### 1. Cookbook Stage Cleanup (`src/cook/cook_build.rs`)
- Line 506, 715: `remove_all(&stage_dir)` before `rename(stage.tmp, stage)`
- Prevents "Directory not empty" during incremental builds

### 2. Cargo Install --Force (`src/cook/script.rs`)
- Line 155: `--force` flag on `cargo install --root`
- Prevents "binary already exists" errors

### 3. KF6 Config (`config/redbear-full.toml`)
- `kf6-kwayland`, `kf6-kidletime` → `"ignore"` (TEMPORARY — blocked on libwayland)
- `31_debug_console.service`: `/scheme/debug/no-preserve -J` with `respawn = true`

### 4. POSIX Named Semaphores (`recipes/core/relibc/`)
- `sem_open`: shm-backed via `shm_open` + `mmap` + `sem_init`
- `sem_close`: `munmap` wrapper
- `sem_unlink`: `shm_unlink` wrapper
- `sem_trywait`: Returns -1 with EAGAIN when acquire fails
- `sem_wait`: Returns -1 with EINVAL on error
- `sem_timedwait`/`sem_clockwait`: Return -1 with ETIMEDOUT on timeout
- Fixed `Semaphore::wait()`: Was returning success when count was 0 (inverted condition)
- **Durable patch**: `local/patches/relibc/P5-named-semaphores.patch` (249 lines)
- **Recipe symlink**: `recipes/core/relibc/P5-named-semaphores.patch` → `local/`

### 5. Documentation
- `GRAPHICAL-BOOT-ASSESSMENT-2026-05-03.md`: Updated with current state
- This file: Comprehensive fix summary
- 20 stale docs archived in `local/docs/archived/`

## Known Limitations (Honest Assessment)

### Semaphore Completeness
- `sem_wait` errno: Sets EINVAL for any error from underlying `wait()`, which can only return `Err(())` for invalid clock_id. Correct in practice for the current code paths.
- `sem_timedwait`/`sem_clockwait`: Set ETIMEDOUT for all errors; cannot distinguish timeout from invalid clock_id with current `wait()` return type. Conservative: ETIMEDOUT covers the common case.
- Named semaphore size: Uses `size_of::<sem_t>()` (4 bytes) for `ftruncate`/`mmap`, but `RlctSemaphore` may be larger. Works currently because internal representation fits.

### Relibc Patch Chain
- `recipes/core/relibc/recipe.toml` currently lists only `P5-named-semaphores.patch`
- Pre-existing relibc modifications (waitid, eventfd, signalfd, etc.) exist in the live source tree but are NOT captured in patches
- A clean `repo fetch relibc` would lose those changes — this is a pre-existing condition, not introduced by this work
- Full relibc patch audit needed as separate task

### Console/Login Surface
- Console login: Available on **framebuffer VT2** (`getty 2`), not serial
- Serial port: Shows daemon logs and stderr output; does not show login prompt in QEMU `-display none` mode
- To access VT2 login: Use `-display gtk` or similar with QEMU

## Build Verification
```
✅ redbear-full: 0 failed recipes, 4GB image
✅ redbear-mini: 0 failed recipes
✅ nm -D libc.so: 11 sem_* symbols exported
✅ Serial console: All daemon output visible (D-Bus, sessiond, greeter, keymapd)
✅ Init chain: Serial probes confirm all services start
✅ Semaphore wait: Fixed inverted condition in sync/semaphore.rs
✅ cbindgen.toml: SEM_FAILED macro exported
```

## Remaining Work (Not In Scope)
1. **libwayland**: Implement MSG_NOSIGNAL and open_memstream in relibc
2. **KF6 re-enable**: When libwayland builds, un-ignore kf6-kwayland/kf6-kidletime
3. **Relibc patch audit**: Capture all pre-existing relibc changes as durable patches
4. **Runtime POSIX tests**: Run test-posix-runtime.sh for behavioral verification
5. **QML gate**: Long-term blocker for KWin/Plasma desktop