Incremental bisection within Step E. E.4 (atomic + mutex + thread) still
crashed at __init_tcb. Drop mutex and thread, keep only std::atomic.
Build.rs still emits cargo:rustc-link-lib=c++_shared via
cpp_link_stdlib('c++_shared'), so the NEEDED entry for libc++_shared.so
in the final .so stays identical. Goal: if this crashes, the issue is
purely the dynamic link against libc++_shared (not thread/mutex code).
If it passes, the issue is actually std::thread or std::mutex use.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Bisection for the __init_tcb+4 crash that Step E introduced: drop the
full Oboe C++ build (200+ files, hundreds of KB of code) and replace
it with ONE tiny cpp/cpp_smoke.cpp that exercises the libc++ features
Oboe uses — std::atomic, std::mutex, std::thread — via an
extern "C" wzp_cpp_smoke() function that's exported but NEVER called
from Rust.
Still compiled with cpp_link_stdlib("c++_shared"), same as Oboe.
libc++_shared.so still copied into gen/android jniLibs. But no Oboe
headers, no Oboe source files, no -llog / -lOpenSLES links.
Hypothesis: if cpp_smoke.cpp alone reproduces the __init_tcb crash,
the trigger is "any libc++_shared link that references
std::thread/std::mutex" and Oboe is not the specific culprit. If it
launches cleanly, Oboe itself (its size, its static constructors, or
a specific header) is responsible — and we then bisect Oboe's
source tree.
fetch_oboe() and add_cpp_files_recursive() are retained in build.rs
with #[allow(dead_code)] so re-enabling the full Oboe compile is a
one-line edit once we've identified what's safe to include.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
