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fix: read ProxyCommand stdin with a blocking os.read instead of select() - #158
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sethtroisi merged 2 commits intoOct 13, 2026
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Windows select() only accepts sockets, so in --proxy-mode the stdin pump died with OSError before any input was forwarded, leaving the runtime without a stdin. A blocking os.read() is equivalent on POSIX (the select waited on just this one fd with no timeout) and works everywhere. The pump direction had no coverage (the existing bridge test stubs the reader thread out), so this adds test_bridge_proxy_mode_pumps_stdin_to_ws, which fails with the select() call in place on Windows and passes with the blocking read on every platform.
sethtroisi
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Oct 12, 2026
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Thanks for the review. I love the tight PR.
sethtroisi
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Oct 13, 2026
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On Windows the stdin pump in
colab ssh --proxy-modedies at startup.select()only accepts sockets there, so the call on the stdin fd raises OSError, the pump thread exits, and the runtime never receives any input. ssh hangs with no way to type.The select() call waited on a single fd with no timeout, so a blocking
os.read()is equivalent on POSIX and also works on Windows. The pump direction had no test coverage (the existing bridge test stubs the reader thread out), so this addstest_bridge_proxy_mode_pumps_stdin_to_ws. It fails with the select() call in place on Windows and passes with the blocking read.Part of the Windows breakage in #85 and #100. The termios crash at startup is separate and already covered by #135.
Verified on Windows 11 with Python 3.12: ruff check clean, all ssh bridge tests pass, and the full suite shows no new failures (the remaining ones are pre-existing platform issues: SIGHUP, prompt_toolkit win32, rich help sorting).
Merge ready.