[issue14576] IDLE cannot connect to subprocess - New solution
New submission from clikkeb : It's a common issue that IDLE cannot start on Windows because "IDLE's subprocess didn't make connection.Either IDLE can't start a subprocess or personal firewall software is blocking the connection." Everyone claim that the user should set the firewal so that IDLE can connect to subprocess via loopback. I found, instead, that this issue is often caused by an incorrect or missing setting of one the following variables: HOME, USERPROFILE or the combination of HOMEPATH and HOMEDRIVE; if these variables don't represent an existent and writable directory, the error occurs. Try setting HOMEPATH to an unexistent or unwritable directory just before launching idle.bat script. Check IdleConf.GetUserCfgDir() in module configHandler.py, where the function os.path.expanduser is called to get the user home directory. You might also temporarly patch GetUserCfgDir, setting the userDir variable to an unexistent path just after it has been initialized via os.path.expanduser (line 202). Should be considered a check on expanduser behaviour? OS: Windows XP Python version: 3.2.2 clikkeb -- components: IDLE messages: 158253 nosy: clikkeb priority: normal severity: normal status: open title: IDLE cannot connect to subprocess - New solution versions: Python 3.2 ___ Python tracker <http://bugs.python.org/issue14576> ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue14576] IDLE cannot connect to subprocess - New solution
clikkeb added the comment: Thanks for your answer. Trying to understand how IDLE uses HOMEPATH and USERPROFILE Windows variables, I have found the following information: 1) it seems that when executed via Windows command prompt (cmd.exe), os.path.expanduser refers to USERPROFILE to determine the user's home directory; 2) analizing the stack traces of the first calls to IdleConf.GetUserCfgDir, you can see that GetUserCfgDir (which calls expanduser) is called three times during IDLE startup: the first two times it refers to USERPROFILE, the third (called via run.py, probably after starting a subprocess) it refers to the combination of HOMEDRIVE and HOMEPATH. (???) 3) when you start IDLE using pythonw, sys.stderr.write(warn) seems to raise an AttributeError exception, which is unhandled. This causes IDLE to stop running when you either start IDLE that way and the user's home directory is unreachable. Due to the Python's tricky behaviour in determining the Windows user's home directory, my opinion would be to consider if it is worth to go further with this discussion or if it could produce a benefit to IDLE. For sure, it gave me a little bit of headache. clikkeb. -- ___ Python tracker <http://bugs.python.org/issue14576> ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue14576] IDLE cannot connect to subprocess - New solution
clikkeb added the comment: I think that lines 207-210 of GetUserCfgDir should be modified like this: try: sys.stderr.write(warn) except (IOError, AttributeError):# < pass#^^ because when you start IDLE via pythonw.exe (that sets sys.stderr to "None"), the function call sys.stderr.write(warn) raises the following exception: AttributeError: 'NoneType' object has no attribute 'write' and IDLE stops running without displaying any exception error, because that exception is unhandled. There is a funcion call to sys.stderr.write also at line 222, just before a "raise SystemExit" statement, which makes ininfluent the missing AttributeError exception handling. -- ___ Python tracker <http://bugs.python.org/issue14576> ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue14576] IDLE cannot connect to subprocess - New solution
clikkeb added the comment: It is one of the possible solutions. In combination with the "writable flag" solution, you might create a class variable in IdleConf (e.g. "user_cfg") that contains the user's home directory; such variable will be initialized to an empty string by IdleConf.__init__. On each call, GetUserCfgDir tries to initialize "user_cfg" only if it is an empty string, otherwise it returns it's content. Anyway, keep in mind that in GetUserConfig there's an unhandled exception (AttributeError) that might be the cause of the "IDLE doesn't start..." issue reported by users. -- ___ Python tracker <http://bugs.python.org/issue14576> ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
