diff --git a/Doc/library/traceback.rst b/Doc/library/traceback.rst index a8412cc93d1..8cb6af9bc84 100644 --- a/Doc/library/traceback.rst +++ b/Doc/library/traceback.rst @@ -341,6 +341,10 @@ capture data for later printing in a lightweight fashion. local variables in each :class:`FrameSummary` are captured as object representations. + .. versionchanged:: 3.12 + Exceptions raised from :func:`repr` on a local variable (when + *capture_locals* is ``True``) are no longer propagated to the caller. + .. classmethod:: from_list(a_list) Construct a :class:`StackSummary` object from a supplied list of diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py index f4161fbf017..602bd2cae0a 100644 --- a/Lib/test/test_traceback.py +++ b/Lib/test/test_traceback.py @@ -2279,6 +2279,9 @@ class TestStack(unittest.TestCase): f' File "{__file__}", line {lno}, in f\n 1/0\n' ) +class Unrepresentable: + def __repr__(self) -> str: + raise Exception("Unrepresentable") class TestTracebackException(unittest.TestCase): @@ -2546,12 +2549,13 @@ class TestTracebackException(unittest.TestCase): linecache.updatecache('/foo.py', globals()) e = Exception("uh oh") c = test_code('/foo.py', 'method') - f = test_frame(c, globals(), {'something': 1, 'other': 'string'}) + f = test_frame(c, globals(), {'something': 1, 'other': 'string', 'unrepresentable': Unrepresentable()}) tb = test_tb(f, 6, None, 0) exc = traceback.TracebackException( Exception, e, tb, capture_locals=True) self.assertEqual( - exc.stack[0].locals, {'something': '1', 'other': "'string'"}) + exc.stack[0].locals, + {'something': '1', 'other': "'string'", 'unrepresentable': ''}) def test_no_locals(self): linecache.updatecache('/foo.py', globals()) diff --git a/Lib/traceback.py b/Lib/traceback.py index 55f80800440..b1a5fd0a26d 100644 --- a/Lib/traceback.py +++ b/Lib/traceback.py @@ -279,7 +279,8 @@ class FrameSummary: self._line = line if lookup_line: self.line - self.locals = {k: repr(v) for k, v in locals.items()} if locals else None + self.locals = {k: _safe_string(v, 'local', func=repr) + for k, v in locals.items()} if locals else None self.end_lineno = end_lineno self.colno = colno self.end_colno = end_colno diff --git a/Misc/ACKS b/Misc/ACKS index b6340414cf7..32475f874c3 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -1590,6 +1590,7 @@ Ed Schouten Scott Schram Robin Schreiber Chad J. Schroeder +Simon-Martin Schroeder Christian Schubert Sam Schulenburg Andreas Schwab diff --git a/Misc/NEWS.d/next/Library/2022-07-08-17-49-12.gh-issue-87822.F9dzkf.rst b/Misc/NEWS.d/next/Library/2022-07-08-17-49-12.gh-issue-87822.F9dzkf.rst new file mode 100644 index 00000000000..7b27f5df45b --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-07-08-17-49-12.gh-issue-87822.F9dzkf.rst @@ -0,0 +1 @@ +When called with ``capture_locals=True``, the :mod:`traceback` module functions swallow exceptions raised from calls to ``repr()`` on local variables of frames. This is in order to prioritize the original exception over rendering errors. An indication of the failure is printed in place of the missing value. (Patch by Simon-Martin Schroeder).