Apply CMake sccache helper to oneapi-math-sycl-blas

todo.md

@@ -28,6 +28,10 @@
 ## Next Checks
 
 - `electron-real-clang-base` should stay store-pure: synthesize its output tree from symlinks only and never `cp`/`rm` against copied toolchain store content.
+- `mkCmakeSccacheAttrs` should not force raw compilers into CMake; the `sccache.links` wrappers should bypass CMake probe invocations while keeping the normal wrapper-selected compiler environment.
+- The probe bypass must inspect `@responseFile` arguments as well, because the cc-wrapper often hides `CMakeFiles/CompilerId` paths inside response files before the inner `wrapped-sccache` sees them.
+- For CMake packages, the practical fallback is to export `SCCACHE_WRAPPED_COMPILER_PASSTHROUGH=1` for the whole `configurePhase` and unset it in `postConfigure`; caching matters in `buildPhase`, not in compiler-ID probes.
+- Apply the shared CMake helper to stalled subpackages too, not just top-level wrappers. `oneapi-math-sycl-blas` is one such case.
 - Build the patched `sccache` package.
 - Run a minimal hello-world derivation with the new `sccacheStdenv` and confirm repeated compiles produce cache hits.
 - If that works, switch current consumers to the ccache-style path and remove obsolete wrapper-patching logic.