Review Request 119497: Report crashes of KDE apps in Apple OS X (1) (fix kcrash, kinit)

[Ian Wadham]

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https://git.reviewboard.kde.org/r/119497/
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(Updated Sept. 15, 2014, 1:39 a.m.)


Review request for KDE Software on Mac OS X, KDE Runtime, kdelibs, and Michael Pyne.


Changes
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This is a new patch for KCrash only (on KDE 4), to prevent it crashing on Apple OS X and to make it start Dr Konqi on Apple OS X only by forking, because starting Dr K via kdeinit4 always fails on Apple OS X. The patch also incorporates ideas arising in previous reviews and closes the relevant issues.

The proposed changes to kinit/kinit.cpp (kdeinit4) have been discontinued temporarily. This is because I appealed for help and answers to some questions about kdeinit4, klauncher, kwrapper and kded4 and how they should interact with each other and with applications, but I was not able to get that help and those answers. So KDE 4 software on MacPorts and Apple OS X will continue as before, making minimal to zero use of those background processes.


Repository: kdelibs


Description
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When a KDE app crashes in Apple OS X, it just disappears from the screen. At the most, the user is invited to report the crash to Apple. AFAIK this has been a problem in KDE on Apple OS X for years, leading to frustration with KDE among Apple users and MacPorts developers and an attitude among KDE developers of "Why does nobody report the problem(s) on bugs.kde.org?"

It is my strong belief that the failure to report crashes of KDE apps in Apple OS X also exists in Frameworks.

So far I have identified a number of portability bugs in KDE on Apple OS X: 1 in KCrash, 1 in kdeinit4 and 5 in Dr Konqi. Patches for the first two are submitted in this review. Patches for three more are submitted in part 2 of this review, against kde-runtime. I am still investigating the other two problems in Dr Konqi - and there could be more than two...

In this review we have two portability problems:

1. KCrash itself crashes (SIGILL) when it tries to close all file descriptors and so Dr Konqi is not started. Some of the FDs belong to the Apple OS X library (COCOA) and it crashes if they are closed prematurely.

2. The preferred way to start Dr K is via a socket message to kdeinit4, but that fails in Apple OS X because kdeinit4 is listening with the wrong socket name. The DISPLAY ID is missing from the end of the name. The fallback is for KCrash to use fork() and exec(), which works, but could cause Dr K to be polluted, depending on the nature of the crash.

This "deafness" of kdeinit4 (and klauncher) could be causing other failures in KDE software in the Apple OS X environment.


Diffs (updated)
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  kdeui/util/kcrash.cpp 45eb46b 

Diff: https://git.reviewboard.kde.org/r/119497/diff/


Testing
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Using Apple OS X 10.7.5 (Lion) on a MacBook Pro, I have installed KDE libs via MacPorts (at version 4.12.5) and I have adapted kdesrc-build to run in an Apple OS X environment and used it to test against the KDE 4.13 branch.  I have been testing with a KDE app that I can crash at will and using stderr and Apple OS X Console log output to determine the outcome.

Please note that I am the -only- KDE developer who has this kind of setup, but I am NOT a KDE core developer. My experience before now has been in KDE Games. However I used to be a UNIX and database guru before I retired in 1998.

I NEED HELP from KDE -core- developers to proceed further. These problems also exist in FRAMEWORKS, but I am as yet unable to build or test Frameworks on Apple OS X. And I am sure there are many more Apple OS X portability problems in KDE software.

Without my patches, Dr Konqi is not started and, if it does get past its own crash, KCrash reports:
KCrash: Attempting to start /kdedev/kde4.13/kde4/lib/kde4/libexec/drkonqi.app/Contents/MacOS/drkonqi from kdeinit
sock_file=/kdedev/kde4.13/home/.kde4.13/socket-Tara.local/kdeinit4__tmp_launch-svPd0L_org.x_0
Warning: connect() failed: : No such file or directory

With my patches, Dr Konqi can always be started directly (using fork()) and it -will- start via kdeinit4 and klauncher but it immediately runs into a privilege problem with Apple OS X (a problem which I am still investigating).

I would not have got this far without help from Michael Pyne, Thomas Lübking and several of the MacPorts developers, as well as the unfailing enthusiasm and encouragement of my friend Marko Käning.


Thanks,

Ian Wadham

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