| 2014-08-17 19:03:46 |
Robert Schroll |
description |
I just wasted many hours tracking down a problem that was caused, in part, by apparmor problems. (See the gory details here: https://github.com/rschroll/beru/issues/56.) Setting aside the issue of why we need a policy group to use a webview (?!), there were several problems that made this problem much harder to track down than it should have been.
1) The plugin didn't alert me about the missing permissions. Obviously this can't work for every permission, but it would be easy to add a warning if a QML file imports Oxide and the apparmor profile doesn't request the webview policy group.
2) Apparmor errors are not logged when a project is run from Qt Creator. I'm sure that, somewhere on the device, there's an apparmor log that recorded that my app was blocked from doing something. (I have no idea where that log is, though.) The plugin should notice when an app exits abnormally and the apparmor log was modified, and it should display the relevant lines from the apparmor log.
3) Not all output from the program appeared in the "Application Output" window in Qt Creator. Instead, a random sampling of the output was displayed. This meant that the relevant line only appeared occasionally in the output, giving the impression of a Heisenbug. Only when I looked in ~/.cache/upstart on the device did I notice that error messages were consistent. |
I just wasted many hours tracking down a problem that was caused, in part, by apparmor problems. (See the gory details here: https://github.com/rschroll/beru/issues/56.) Setting aside the issue of why we need a policy group to use a webview (?!), there were several problems that made this problem much harder to track down than it should have been.
1) The plugin didn't alert me about the missing permissions. Obviously this can't work for every permission, but it would be easy to add a warning if a QML file imports Oxide and the apparmor profile doesn't request the webview policy group.
2) Apparmor errors are not logged when a project is run from Qt Creator. I'm sure that, somewhere on the device, there's an apparmor log that recorded that my app was blocked from doing something. (I have no idea where that log is, though.) The plugin should notice when an app exits abnormally and the apparmor log was modified, and it should display the relevant lines from the apparmor log.
3) Not all output from the program appeared in the "Application Output" window in Qt Creator. Instead, a random sampling of the output was displayed. This meant that the relevant line only appeared occasionally in the output, giving the impression of a Heisenbug. Only when I looked in ~/.cache/upstart on the device did I notice that error messages were consistent.
If it matters, I'm on 14.04 and using the SDK team PPA. |
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