[tbot] Negative timeout error with acquire_linux()

[Harald Seiler]

Hi Niel,

On Thu, 2018-11-29 at 10:52 +0100, Niel Fourie wrote:
> Hi Harald,
> 
> Just FYI, with tbot release 0.6.3, on Fedora Core 28 with Python 3.6.6, 
> when using acquire_linux(), on waiting for the login prompt, I get this 
> exception quite a lot:
> 
> 
> │   Traceback (most recent call last):
> │     File "/home/lusus/workspace/git/tbot/tbot/main.py", line 220, in main
> │       testcases[tc]()
> │     File "/home/lusus/workspace/git/tbot/tbot/__init__.py", line 55, 
> in wrapped
> │       result = tc(*args, **kwargs)
> │     File "/home/lusus/workspace/tbot-tutorial/tc.py", line 20, in 
> my_testcase
> │       lnx = cx.enter_context(tbot.acquire_linux(b))
> │     File "/home/lusus/workspace/git/tbot/tbot/selectable.py", line 
> 191, in acquire_linux
> │       return LinuxMachine(b)
> │     File "/home/lusus/workspace/git/tbot/tbot/machine/board/linux.py", 
> line 230, in __init__
> │       log = self.boot_to_shell(channel.SkipStream(ev, 
> len(last_command) + 1))
> │     File "/home/lusus/workspace/git/tbot/tbot/machine/board/linux.py", 
> line 95, in boot_to_shell
> │       chan.read_until_prompt("TBOTLOGIN", timeout=0.2, must_end=False)
> │     File 
> "/home/lusus/workspace/git/tbot/tbot/machine/channel/channel.py", line 
> 332, in read_until_prompt
> │       new = self.recv(timeout=timeout_remaining)
> │     File 
> "/home/lusus/workspace/git/tbot/tbot/machine/channel/subprocess.py", 
> line 73, in recv
> │       r, _, _ = select.select([self.pty_master], [], [], timeout)
> │   ValueError: timeout must be non-negative
> 
> If I make the timeout=1 in tbot/tbot/machine/board/linux.py line 95, 
> then the issue disappears. As discussed on chat, adding an extra check 
> may work around it. My setup seems to exhibit quite a few quirks. Sorry!

Fixed in 5fa305618de86f27d2e24ee2ff943edac0c8ee53[1].

[1]: https://github.com/Rahix/tbot/commit/5fa305618de86f27d2e24ee2ff943edac0c8ee53

> Best regards,
> Niel Fourie
> 
-- 
Harald

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