WIP: windows-already-loaded-dll-detection

[rwgk]

WIP-WIP-WIP

This is to address CI failures observed under (e.g.) PRs #1856, #1902

They seem to be triggered by the CTK 13.2.1 release.

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[rwgk]

Cursor GPT-5.4 Extra High Fast

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What I know

• In cuda_pathfinder/cuda/pathfinder/_dynamic_libs/dynamic_lib_subprocess.py, the first load_nvidia_dynamic_lib("cupti") succeeds as a fresh load, so the child process is loading CUPTI itself rather than finding it preloaded.
• For that first load, cuda_pathfinder/cuda/pathfinder/_dynamic_libs/load_nvidia_dynamic_lib.py follows the normal found-on-disk path and ends up in cuda_pathfinder/cuda/pathfinder/_dynamic_libs/load_dl_windows.py via load_with_abs_path(...).
• The failure happens on the second uncached call, where check_if_already_loaded_from_elsewhere(...) is supposed to rediscover the same loaded DLL before trying to load it again.
• That rediscovery used only GetModuleHandleW(dll_name). In the failing jobs, it returns no match, so the subprocess raises not loaded_dl_no_cache.was_already_loaded_from_elsewhere.
• The correlation is strong with the new Windows CUPTI build: the failing jobs show cupti64_2026.1.0.dll, while older Windows jobs using cupti64_2025.2.1.dll and cupti64_2025.3.1.dll pass.

What I do not know

• I do not have proof of why GetModuleHandleW("cupti64_2026.1.0.dll") misses after that DLL has been loaded.
• I cannot yet say whether that is a change in CUPTI itself, a Windows loader quirk exposed by this CUPTI build, or some interaction between the two.
• I have not found a public NVIDIA note or Windows API note that specifically explains this exact cupti64_2026.1.0.dll behavior.

[rwgk]

The fix is simply #1906

Closing this PR. I'll work on more robust (to new DLL names) support under a new PR.

[cpcloud]

Root cause analysis

The win-64 test_load_nvidia_dynamic_lib[cupti] failures on #1856 / #1902 (and main's scheduled CI) are caused by a new cupti DLL version not being in the descriptor catalog.

Timeline:

• nvidia-cuda-cupti 13.2.23 (Mar 9) shipped cupti64_2026.1.0.dll — in the catalog, tests pass
• nvidia-cuda-cupti 13.2.75 (Apr 13) shipped cupti64_2026.1.1.dll — not in the catalog, tests fail

Mechanism:

1. see_what_works step runs before extra wheels are installed → cupti not available → "not found" → passes
2. Install cuda.pathfinder extra wheels for testing installs cuda-toolkit[cupti]==13.* → pulls nvidia-cuda-cupti 13.2.75 with cupti64_2026.1.1.dll
3. all_must_work step runs → cupti loads fine via abs path → but GetModuleHandleW iterates known DLL names (newest is cupti64_2026.1.0.dll) → no match → was_already_loaded_from_elsewhere returns False → RuntimeError

On this PR's approach: The EnumProcessModules fallback still matches against desc.windows_dlls (the known basename set). If cupti64_2026.1.1.dll isn't in that tuple, the enumeration won't find it either — same name set, different lookup method. The catalog needs "cupti64_2026.1.1.dll" added regardless.

Verified by inspecting the actual wheel contents:

# 13.2.23 (old, working)
nvidia/cu13/bin/x86_64/cupti64_2026.1.0.dll
# 13.2.75 (new, breaking)
nvidia/cu13/bin/x86_64/cupti64_2026.1.1.dll