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When using blocking mode in the remote debugging profiler, ptrace calls to seize threads can fail with EPERM if the thread has exited between listing and attaching, is in a special kernel state, or is already being traced. Previously this raised a RuntimeError that was caught by the Python sampling loop,and retried indefinitely since EPERM is a persistent condition that will not resolve on its own. Treat EPERM the same as ESRCH by returning 1 (skip this thread) instead of -1 (fatal error). This allows profiling to continue with the threads that can be traced rather than entering an endless retry loop printing the same error message repeatedly.
thunder-coding pushed a commit to thunder-coding/cpython that referenced this pull request
Feb 15, 2026…honGH-143368) When using blocking mode in the remote debugging profiler, ptrace calls to seize threads can fail with EPERM if the thread has exited between listing and attaching, is in a special kernel state, or is already being traced. Previously this raised a RuntimeError that was caught by the Python sampling loop,and retried indefinitely since EPERM is a persistent condition that will not resolve on its own. Treat EPERM the same as ESRCH by returning 1 (skip this thread) instead of -1 (fatal error). This allows profiling to continue with the threads that can be traced rather than entering an endless retry loop printing the same error message repeatedly.