The commit r257866 (https://github.com/llvm-mirror/compiler-rt/commit/b78f9c1f623e5faa4cca68227ab536ae80f9fc16, differential revision http://reviews.llvm.org/D15301, which is slightly different than the commit) introduced a test failure in Darwin/ignored-interceptors.mm. When ignore_interceptors_accesses=1, we only check !thr_->is_inited in the constructor of ScopedInterceptor, which then skips ThreadIgnoreBegin, but the destructor still calls ThreadIgnoreEnd:
ScopedInterceptor::ScopedInterceptor(...) { Initialize(thr); if (!thr_->is_inited) return; ... if (flags()->ignore_interceptors_accesses) ThreadIgnoreBegin(thr_, pc_); } ScopedInterceptor::~ScopedInterceptor() { if (flags()->ignore_interceptors_accesses) ThreadIgnoreEnd(thr_, pc_); ... }