Does py-spy record ignore threads that don’t contain any Python stack frame by default?

I have a Python program with a native extension (that happens to be written in Rust). That extension starts a thread (with Rust’s std::thread::spawn) to do some CPU-intensive work in parallel with other work. The child thread never runs a Python interpreter. The SVG output of the profiler is missing everything in the second thread. --native does show Rust stack frames, but only in the parent thread. Adding --threads adds the ID of the parent thread to the output but nothing else. Adding --idle doesn’t seem to change anything for this program.

When using py-spy dump --pid (at the right time) however, the stack of both threads is printed correctly.

Can I use py-spy to profile both threads?