Description of problem:

The "foo?" ipython help command raises an exception in sage command-line
interactive interpreter. However, "help(foo)" works normally.


Version-Release number of selected component (if applicable):
sagemath-8.6-1.fc30.x86_64

How reproducible:
always


Steps to Reproduce:

$ sage
sage: matrix?

(also on clean user account with no custom ipython etc. config)


Actual results:
Raises exception:
Traceback (most recent call last):
  File "<ipython-input-3-d02b15b27f6d>", line 1, in <module>
    get_ipython().magic('pinfo matrix')
  File "/usr/lib64/sagemath/site-packages/IPython/core/interactiveshell.py", line 2160, in magic
    return self.run_line_magic(magic_name, magic_arg_s)
  File "/usr/lib64/sagemath/site-packages/IPython/core/interactiveshell.py", line 2081, in run_line_magic
    result = fn(*args,**kwargs)
  File "<decorator-gen-74>", line 2, in pinfo
  File "/usr/lib64/sagemath/site-packages/IPython/core/magic.py", line 188, in <lambda>
    call = lambda f, *a, **k: f(*a, **k)
  File "/usr/lib64/sagemath/site-packages/IPython/core/magics/namespace.py", line 61, in pinfo
    namespaces=namespaces)
  File "/usr/lib64/sagemath/site-packages/IPython/core/interactiveshell.py", line 1536, in _inspect
    enable_html_pager=self.enable_html_pager, **kw)
  File "/usr/lib64/sagemath/site-packages/IPython/core/oinspect.py", line 715, in pinfo
    info = self._get_info(obj, oname, formatter, info, detail_level)
  File "/usr/lib64/sagemath/site-packages/IPython/core/oinspect.py", line 616, in _get_info
    info = self._info(obj, oname=oname, info=info, detail_level=detail_level)
  File "/usr/lib64/sagemath/site-packages/IPython/core/oinspect.py", line 765, in _info
    ds = getdoc(obj)
  File "sage/misc/lazy_import.pyx", line 354, in sage.misc.lazy_import.LazyImport.__call__ (build/cythonized/sage/misc/lazy_import.c:3648)
    return self.get_object()(*args, **kwds)
  File "/usr/lib64/python3.7/site-packages/sage/misc/sageinspect.py", line 1917, in sage_getdoc
    s = sage.misc.sagedoc.format(r, embedded=(embedded_override or EMBEDDED_MODE))
  File "/usr/lib64/python3.7/site-packages/sage/misc/sagedoc.py", line 711, in format
    s = detex(s, embedded=embedded)
  File "/usr/lib64/python3.7/site-packages/sage/misc/sagedoc.py", line 228, in detex
    s = sphinxify(s, format='text')
  File "/usr/lib64/python3.7/site-packages/sage/misc/sphinxify.py", line 97, in sphinxify
    confoverrides, None, None, True)
  File "/usr/lib/python3.7/site-packages/sphinx/application.py", line 160, in __init__
    raise ApplicationError(__('Source directory and destination '
ApplicationError: Source directory and destination directory cannot be identical


Expected results:
Should show help normally as in Ipython.


Additional info:
-