Description
Bug report
Bug description:
Details
The traceback module's various functions for inspecting an exception leaks surrounding code when used to inspect an exception originating from an exec
or eval
call. I discovered this using traceback.format_exception
but it applies to traceback.print_exc
and the other ones that call or are called by those as well.
Specifically when compiled for "exec" mode using compile
, and the exec
:ed code inherits the context from which exec
was called.
In this example, the comment on the first line is included in the printed traceback.
# Hi, I'm in the error message
import traceback
try:
exec(compile("tuple()[0]", "s", "exec"))
except:
traceback.print_exc()
This prints:
Traceback (most recent call last):
File "<filename>", line 4, in <module>
exec(compile("tuple()[0]", "s", "exec"))
File "s", line 1, in <module>
# Hi, I'm in the error message
IndexError: tuple index out of range
It seems that whatever line number the error is on in the exec
:ed code is applied to the calling file instead of the exec
:ed code.
Changing line 4 in the example above to exec("tuple()[0]")
avoids the issue, and no info regarding the line is printed by traceback. This behavior is in line with what python outputs when the exception is not caught:
# Hi, I'm not in the error message
exec(compile("tuple()[0]", "s", "exec"))
results in:
Traceback (most recent call last):
File "<filename>", line 2, in <module>
exec(compile("tuple()[0]", "s", "exec"))
File "s", line 1, in <module>
IndexError: tuple index out of range
Summary
Example code
# Hi, I'm in the error message
import traceback
try:
exec(compile("tuple()[0]", "s", "exec"))
except:
traceback.print_exc()
Expected behaviour
Should print the following:
Traceback (most recent call last):
File "<filename>", line 4, in <module>
exec(compile("tuple()[0]", "s", "exec"))
File "s", line 1, in <module>
IndexError: tuple index out of range
Actual behaviour
Prints this:
Traceback (most recent call last):
File "<filename>", line 4, in <module>
exec(compile("tuple()[0]", "s", "exec"))
File "s", line 1, in <module>
# Hi, I'm in the error message
IndexError: tuple index out of range
CPython versions tested on:
3.8, 3.10, 3.11, 3.12
Operating systems tested on:
Linux, Windows