py3: make doctest pass in repl module

[vklein]

Fix the failling doctests in the sage.repl module :

sage -t --long src/sage/repl/configuration.py  # 2 doctests failed
sage -t --long src/sage/repl/ipython_tests.py  # 5 doctests failed
sage -t --long src/sage/repl/interpreter.py  # 1 doctest failed
sage -t --long src/sage/repl/ipython_kernel/widgets_sagenb.py  # 2 doctests failed
sage -t --long src/sage/repl/ipython_kernel/interact.py  # 1 doctest failed

[vklein]

New commits:

​13b9f22

Trac #26881: py3 Fix repl module for python3

[chapoton]

Well, I find it suspect that OrderedDict? does not display in the given order in py2..

But let us keep that for another ticket..

[chapoton]

I still get

sage -t --long src/sage/repl/attach.py  # 4 doctests failed

namely

sage -t --long src/sage/repl/attach.py
**********************************************************************
File "src/sage/repl/attach.py", line 36, in sage.repl.attach
Failed example:
    try:
        attach(src)
    except Exception:
        traceback.print_exc()
Expected:
    Traceback (most recent call last):
    ...
        exec(preparse_file(f.read()) + "\n", globals)
      File "<string>", line 3, in <module>
    ValueError: third
Got:
    <BLANKLINE>
**********************************************************************
File "src/sage/repl/attach.py", line 45, in sage.repl.attach
Failed example:
    detach(src)
Expected nothing
Got:
    Traceback (most recent call last):
      File "<doctest sage.repl.attach[10]>", line 2, in <module>
        attach(src)
      File "sage/misc/lazy_import.pyx", line 354, in sage.misc.lazy_import.LazyImport.__call__ (build/cythonized/sage/misc/lazy_import.c:3683)
        return self.get_object()(*args, **kwds)
      File "/home/u1/chapoton/sage3/local/lib/python3.6/site-packages/sage/repl/attach.py", line 356, in attach
        load(filename, globals(), attach=True)
      File "/home/u1/chapoton/sage3/local/lib/python3.6/site-packages/sage/repl/load.py", line 272, in load
        exec(preparse_file(f.read()) + "\n", globals)
      File "<string>", line 3, in <module>
    ValueError: third
**********************************************************************
File "src/sage/repl/attach.py", line 48, in sage.repl.attach
Failed example:
    try:
        attach(src)
    except Exception:
        traceback.print_exc()
Expected:
    Traceback (most recent call last):
    ...
        exec(code, globals)
      File ".../foobar.sage....py", line ..., in <module>
        raise ValueError("third")   # this should appear in the source snippet
    ValueError: third
Got:
    <BLANKLINE>
**********************************************************************
File "src/sage/repl/attach.py", line 58, in sage.repl.attach
Failed example:
    detach(src)
Expected nothing
Got:
    Traceback (most recent call last):
      File "<doctest sage.repl.attach[13]>", line 2, in <module>
        attach(src)
      File "sage/misc/lazy_import.pyx", line 354, in sage.misc.lazy_import.LazyImport.__call__ (build/cythonized/sage/misc/lazy_import.c:3683)
        return self.get_object()(*args, **kwds)
      File "/home/u1/chapoton/sage3/local/lib/python3.6/site-packages/sage/repl/attach.py", line 356, in attach
        load(filename, globals(), attach=True)
      File "/home/u1/chapoton/sage3/local/lib/python3.6/site-packages/sage/repl/load.py", line 266, in load
        exec(code, globals)
      File "/home/u1/chapoton/.sage/temp/atlas/6848/foobar.sage8jw3wb2i.py", line 7, in <module>
        raise ValueError("third")   # this should appear in the source snippet
    ValueError: third

[vklein]

I don't get that attach.py tests pass (as the whole module) in py2 and py3 on my computers. Do you use optional modules ?

[chapoton]

indeed, the tests pass when run alone on the patchbot machine and another machine. So they only fail in the patchbot run.

Note that the failures seems to be a shift in the answers: each doctests receives the output of the previous doctest..