[New-bugs-announce] [issue27167] subprocess reports signal as negative exit status, not documented

[David MacKenzie]

New submission from David MacKenzie:

If a command run by subprocess.check_call() exits because of a signal, e.g. SIGPIPE, Popen._handle_exitstatus() encodes the signal number as a negative return code. check_call() then raises that as a CalledProcessError, which describes it as "returned non-zero exit status -13". This is misleading and undocumented. 

CalledProcessError.__str__() should check if self.returncode is negative and if so return a string indicating that it was "signal 13", not "exit status -13". Better yet, it should include the descriptive name of the signal, e.g., SIGPIPE.

And, the documentation for the subprocess module should note that a signal is converted into a negative returncode.

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components: Library (Lib)
messages: 266758
nosy: dmacnet
priority: normal
severity: normal
status: open
title: subprocess reports signal as negative exit status, not documented
type: behavior
versions: Python 3.5

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue27167>
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