fix: Windows (MSVC) native and CUDA builds#1
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Three build-script fixes, each a hard build failure on Windows: - canonicalize_llama_cpp_dir returned \?\-prefixed verbatim paths, which cl.exe cannot resolve in -I include dirs (fatal error C1083 on ggml-backend.h). Strip the verbatim prefix after canonicalizing. - The target_os link-lib match had no windows arm; ggml-cpu's CPU detection calls RegOpenKeyExA/RegQueryValueExA/RegCloseKey, leaving three unresolved __imp_Reg* externals at link time. Link advapi32. - emit_cuda_link_flags was Linux-only and its lib set (cudart_static/culibos/ dl/rt/pthread) is Unix-specific, so --features cuda compiled every kernel then failed to link. Add a Windows variant emitting the cudart/cublas/ cublasLt/cuda import libs plus the lib\x64 search path, which cuda_library_dir misses when the bare lib parent exists. Validated on Windows 11 (MSVC 14.51, CUDA 12.2, RTX 4090) against mainline llama.cpp b10054: CPU and CUDA builds link and run; CPU vs GPU eval results on Bonsai-27B-Q1_0 are identical. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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smanaton due to an error
July 17, 2026 18:00
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canonicalize() can return \\?\UNC\server\share\...; stripping only \\?\ left a relative UNC\... path. Map that form to \\server\share\... and plain \\?\C:\... to C:\... so MSVC/CMake include paths stay absolute.
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Summary
Three
build.rsfixes — each a hard build/link failure on Windows:canonicalize()returns\\?\...paths that MSVCcl.execannot use in-Idirs. Strip carefully:\\?\C:\foo→C:\foo\\?\UNC\server\share→\\server\sharecudart,cublas,cublasLt,cuda) pluslib\x64search path when CUDA is enabled.Test plan
Notes
Fork staging: smanaton#1
Recommend merging before the prefer-mainline-llama PR.