Running doctests from within Sage doesn't work

[roed]

Running doctests from within Sage results in any test that has output failing. For example:

sage: run_doctests(sage.algebras.algebra)
Doctesting /Users/roed/sage/sage-5.9.beta0/devel/sage/sage/algebras/algebra.py
Running doctests with ID 2013-03-17-01-02-17-09f21e8e.
Doctesting 1 file.
sage -t /Users/roed/sage/sage-5.9.beta0/devel/sage/sage/algebras/algebra.py
**********************************************************************
File "/Users/roed/sage/sage-5.9.beta0/devel/sage/sage/algebras/algebra.py", line 29, in sage.algebras.algebra.is_Algebra
Failed example:
    is_Algebra(R)
Expected:
    True
Got:
    True
**********************************************************************
File "/Users/roed/sage/sage-5.9.beta0/devel/sage/sage/algebras/algebra.py", line 31, in sage.algebras.algebra.is_Algebra
Failed example:
    sig_on_count()
Expected:
    0
Got:
    0
**********************************************************************
1 item had failures:
   2 of   4 in sage.algebras.algebra.is_Algebra
    [3 tests, 2 failures, 0.1 s]
----------------------------------------------------------------------
sage -t /Users/roed/sage/sage-5.9.beta0/devel/sage/sage/algebras/algebra.py  # 2 doctests failed
----------------------------------------------------------------------
Total time for all tests: 0.1 seconds
    cpu time: 0.1 seconds
    cumulative wall time: 0.1 seconds

This is the result of IPython coloring the output.

Apply

• 14290.patch​
• trac_14290_ansi_escapes_indication.patch​

[roed]

I couldn't figure out a way to doctest this fix (since the problem only occurred when running doctests from IPython), but it's ready for review.

[vbraun]

Positive review to your patch.

I still think that it would be nice to have a note added to the diff that there were ansi escape sequences, since they don't get printed and you are otherwise just left with two identical strings which makes it non-obvious why the doctest failed. So I rescued that piece of the patch from #14359.

[roed]

Your patch looks good too.