.cargo/config.toml

@@ -1,10 +1,14 @@
-# Fix: whisper.cpp (whisper-rs-sys) is configured by the cmake crate, which
-# hardcodes opt_level(0) and overwrites CMake's default MSVC Release flags
-# (/O2 /Ob2 /DNDEBUG) with unoptimized ones — ggml's CPU kernels were compiled
-# at /Od with asserts on, making CPU-only transcription ~40x slower than real
-# time (bench finding W1, docs/benchmarks/2026-07-parakeet-vs-whisper.md).
-# cc-rs appends these env flags after its own, so they win for every native
-# dep. MSVC-only flags are fine: WhispAssist is a Windows-native app.
+# Fix: whisper.cpp (whisper-rs-sys) is configured by the cmake crate, which on
+# MSVC *without an explicit generator* overwrites CMAKE_C_FLAGS_RELEASE with
+# unoptimized flags (it also strips any -O*/O* flag from CFLAGS, so env
+# optimization flags can't survive). Result: ggml's CPU kernels compiled at
+# /Od — CPU-only transcription ran ~40x slower than real time (bench finding
+# W1, docs/benchmarks/2026-07-parakeet-vs-whisper.md). With a generator set,
+# cmake-rs skips that override (`if generator.is_none() && msvc` in
+# cmake-0.1.58) and CMake's default Release flags (/O2 /Ob2 /DNDEBUG) apply.
+# Ninja ships with VS Build Tools; builds already require vcvars64 (which puts
+# it on PATH). NDEBUG kept explicitly so C deps never build with asserts on.
 [env]
-CFLAGS = "/O2 /DNDEBUG"
-CXXFLAGS = "/O2 /DNDEBUG"
+CMAKE_GENERATOR = "Ninja"
+CFLAGS = "/DNDEBUG"
+CXXFLAGS = "/DNDEBUG"