[issue20074] open() of read-write non-seekable streams broken

[Ken Teh]

Ken Teh <teh at anl.gov> added the comment:

It works on macos but not on linux, ie, I have a usb-serial dongle connected to a serial device (a CAMAC controller), and I do an os.open() with 'wb+', followed by a io.fdopen().  I can talk to my device on macos BigSur 11.2, buffered, but not on Linux which throws the non-seekable error when I do the io.fdopen().

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nosy: +ken.teh

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue20074>
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