Both coli's cuda_binary() and doctor.py's cuda_linkage() detect CUDA support
by running `ldd` on the engine binary and looking for a linked libcudart —
but that's Linux-only (cuda_binary() checks sys.platform != "linux", and
cuda_linkage() checks os.name != "posix", both short-circuiting to False on
win32). Windows CUDA_DLL=1 builds never link libcudart at all: glm.exe loads
coli_cuda.dll dynamically via LoadLibrary at startup (backend_loader.c), so
there's no import-table entry for ldd/dumpbin to find in the first place.
The practical effect: `coli doctor` always reported "NVIDIA GPU detected but
the engine is CPU-only" on Windows, and `coli run/chat/serve --gpu ...`
always hard-exited with "--gpu needs the CUDA build" — even on a correctly
built CUDA_DLL=1 binary with coli_cuda.dll sitting right next to glm.exe.
Fix: on win32, detect a COLI_CUDA build by scanning glm.exe for the marker
string "[CUDA] mode: routed experts", which only exists in code compiled
under #ifdef COLI_CUDA (see glm.c's cuda init block), then confirm
coli_cuda.dll actually sits next to the binary — mirroring the Linux
"linked but missing" distinction. Linux/macOS detection is unchanged.
Verified on Windows 11 with mingw-w64 GCC 16.1.0 + CUDA 13.2 + RTX 5080:
`coli doctor` now reports "CUDA engine and devices are available", and
`coli run --gpu 0 --vram 8` populates VRAM (confirmed via the engine's own
"[CUDA] resident set: N tensors, X GB VRAM" runtime log) instead of exiting.
Two related crash bugs in the Python planning layer:
P1: Path.read_text() without encoding= defaults to locale.getpreferredencoding()
(cp1252 on most Windows installs). HuggingFace config.json is UTF-8 — if it
contains any non-ASCII byte (Chinese fields, accented chars, emoji in
metadata), read_text() raises UnicodeDecodeError. In doctor.py this is
caught and mis-reported as 'config.json is missing or invalid' (false
negative); in build_plan() called directly it is an uncaught crash.
Fixed: read_text(encoding='utf-8') in both resource_plan.py and doctor.py.
P2: int(cfg.get('kv_lora_rank', 0)) crashes with TypeError if the key is
present but null (JSON null). dict.get() returns the default only when
the key is ABSENT; a null value returns None, and int(None) raises
TypeError. The engine validates against malformed configs in C but the
Python planner did not.
Fixed: int(cfg.get(key) or 0) — coerces both missing and null to 0.
Applied to all 8 int(cfg.get(...)) calls in build_plan().
Co-authored-by: woolcoxm <13604288+woolcoxm@users.noreply.github.com>
On Windows, os.access(path, os.X_OK) always returns True for any existing
file (NTFS has no execute bit; executability is governed by file extension,
not mode bits). So the test_non_executable_engine test — which chmods the
engine to 0o644 and expects 'fail' — could never pass on Windows.
Fixed doctor.py to use a platform-aware check: on Windows, any existing
file is executable; on POSIX, honor the mode bits via os.access(X_OK).
Fixed the test to assert the correct per-platform expectation: 'pass' on
Windows (chmod is a no-op for executability), 'fail' on POSIX.
Co-authored-by: woolcoxm <13604288+woolcoxm@users.noreply.github.com>