Catch/handle error from __repr__

[blueyed]

repr() might trigger database queries in Django, and then e.g. pytest-django
might throw an exception that disallows this.

Therefore when using better-exceptions from a debugger it might crash it there.

I think the call to repr should be protected against this.

.venv/lib/python3.7/site-packages/pdb.py:1325: in _format_extra_exception
    fmt_exc = list(better_formatter.format_exception(etype, evalue, tb))
../../Vcs/better-exceptions/better_exceptions/formatter.py:322: in format_exception
    for line in self._format_exception(value, tb):
../../Vcs/better-exceptions/better_exceptions/formatter.py:311: in _format_exception
    formatted, colored_source = self.format_traceback(exc_traceback)
../../Vcs/better-exceptions/better_exceptions/formatter.py:274: in format_traceback
    formatted, colored = self.format_traceback_frame(tb)
../../Vcs/better-exceptions/better_exceptions/formatter.py:234: in format_traceback_frame
    filename, lineno, function, source, color_source, relevant_values = self.get_traceback_information(tb)
../../Vcs/better-exceptions/better_exceptions/formatter.py:227: in get_traceback_information
    relevant_values = self.get_relevant_values(source, frame, tree)
../../Vcs/better-exceptions/better_exceptions/formatter.py:135: in get_relevant_values
    values.append((text, col, self.format_value(val)))
../../Vcs/better-exceptions/better_exceptions/formatter.py:117: in format_value
    v = repr(v)
../../Vcs/django/django/db/models/query.py:250: in __repr__
    data = list(self[:REPR_OUTPUT_SIZE + 1])
../../Vcs/django/django/db/models/query.py:274: in __iter__
    self._fetch_all()
../../Vcs/django/django/db/models/query.py:1242: in _fetch_all
    self._result_cache = list(self._iterable_class(self))
../../Vcs/django/django/db/models/query.py:55: in __iter__
    results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
../../Vcs/django/django/db/models/sql/compiler.py:1098: in execute_sql
    cursor = self.connection.cursor()
../../Vcs/django/django/db/backends/base/base.py:260: in cursor
    return self._cursor()
../../Vcs/django/django/db/backends/base/base.py:235: in _cursor
    self.ensure_connection()
E   Failed: Database access not allowed, use the "django_db" mark, or the "db" or "transactional_db" fixtures to enable it.

[Delgan]

Good catch!

I think this is implemented but not yet released.

[Qix-]

I can do a release sometime today :)

[blueyed]

Note that pytest's Fail exception is derived from BaseException, so would not be caught there.