New submission from Jeroen Demeyer <[email protected]>: Displaying the source code in tracebacks for Cython-compiled extension modules in IPython no longer works due to PEP 302. Various fixes are possible, the two most obvious ones are:
1. linecache should continue searching for the source file even if loader.get_source() returns None. 2. the method ExtensionFileLoader.get_source() should be removed (instead of being implemented and returning None). Now why was this broken and how do the above fix that? When IPython needs to display a traceback, it uses linecache.getlines() to get the source code to display. For Cython extensions, the filename is a correct *relative* filename (it must be a relative filename since Cython does not know where the sources will be after installation). Since the filename is relative, linecache does not immediately find it, so it looks for a PEP 302 loader. For extension modules (Cython or not), it finds an instance of ExtensionFileLoader. If the loader has a get_source() method, then it uses that to get the sources. Since ExtensionFileLoader.get_source() returns None, linecache stops looking further for sources. Instead, what should happen is that linecache continues looking for the sources in sys.path where it has a chance of finding them (if they are installed somewhere in sys.path). ---------- components: Library (Lib) messages: 311829 nosy: erik.bray, jdemeyer priority: normal severity: normal status: open title: Tracebacks from Cython modules no longer work _______________________________________ Python tracker <[email protected]> <https://bugs.python.org/issue32797> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
