+Note that Clang packages typically don't include cross-compiled builds of
+compiler-rt, libcxx, or libcxxabi, for `libclang_rt.builtins-wasm32.a`,
+`libc++.a`, or `libc++abi.a`, respectively, so they may not be usable without
+extra setup. This is one of the things [wasi-sdk] simplifies, as it includes
+cross-compiled builds of compiler-rt, `libc++.a`, and `libc++abi.a`.
+
+## Building in pthread support
+
+To enable pthreads support via the [wasi-threads] proposal, follow the above
+build directions with one addition: `make ... THREAD_MODEL=posix`. This creates
+additional artifacts in `sysroot/lib/wasm32-wasi-threads` to support `--target
+wasm32-wasi-threads`.