Interrupt testing

[jdemeyer]

This ticket aims to provide a way to test interrupts and the sig_on()/sig_off() mechanism.

This also patches $SAGE_ROOT/local/bin/sage-doctest to check that all doctests have a balanced sig_on()/sig_off() count.

Patch chain: #9678, #10061, #10258, #10030, #10018, #9640

[jdemeyer]

On OS X, I get doctest "failures"::

**********************************************************************
File "/Users/jdemeyer/sage-4.6.2.alpha0/devel/sage/sage/tests/interrupt.pyx", line 502:
    sage: print '---'; print Popen(['sage', '-c', cmd], stdout=PIPE, stderr=PIPE).communicate()[1]  # long time
Expected:
    ---
    ...
    ------------------------------------------------------------------------
    Unhandled SIGABRT: An abort() occurred in Sage.
    This probably occurred because a *compiled* component of Sage has a bug
    in it and is not properly wrapped with sig_on(), sig_off(). You might
    want to run Sage under gdb with 'sage -gdb' to debug this.
    Sage will now terminate.
    ------------------------------------------------------------------------
    ...
Got:
    ---
    <BLANKLINE>
    ------------------------------------------------------------------------
    Unhandled SIGABRT: An abort() occurred in Sage.
    This probably occurred because a *compiled* component of Sage has a bug
    in it and is not properly wrapped with sig_on(), sig_off(). You might
    want to run Sage under gdb with 'sage -gdb' to debug this.
    Sage will now terminate.
    ------------------------------------------------------------------------
    /Users/jdemeyer/sage-4.6.2.alpha0/local/bin/sage-sage: line 783: 61015 Abort trap              sage-eval "$@"
    <BLANKLINE>
**********************************************************************

It looks to me that the "Got" text matches the "Expected" text, so why is this a failure?

[vbraun]

I think the issue is that "..." expects to match something but does not match the empty line <BLANKLINE>. Note the difference between

• Linux: will print stack backtrace before "Unhandled SIGABRT", and
• OSX: does not print stack backtrace.

For example, changing

sage: print '---'; print Popen(['sage', '-c', cmd], stdout=PIPE, stderr=PIPE).communicate()[1]  # long time

to

sage: print '---'; print 'backtrace:'; print Popen(['sage', '-c', cmd], stdout=PIPE, stderr=PIPE).communicate()[1]  # long time

fixes the doctest on OSX, as now at least 'backtrace:' gets matched by the "...".

[jdemeyer]

SCRIPTS patch, patch for sage-doctest

[jdemeyer]

Okay, I didn't know that ... needs to match at least one non-blank character (apparently). I fixed it in the most simple way by replacing ---\n... by -...

[vbraun]

Looks good! I tested it on bsd.math and all doctests pass.

[jdemeyer]

SAGELIB patch

[jdemeyer]

Additional SAGELIB patch

[vbraun]

Looks good.