[Qgis-developer] projections, plugins, and R: segfault

[Barry Rowlingson]

2009/3/19 Paolo Cavallini <cavallini at faunalia.it>:
> Hi all.
> I can replicate the mysterious R-plugin crash: it happens systematically
> when I enable on the fly CRS transformation with several rasters and
> vectors in different projections.
> QGIS self compiled from svn, fresh.
>
> Here is the message:
>
> Critical: QgsCoordinateReferenceSystem::createFromWkt -- theWkt is
> uninitialised, operation failed
> Critical: QgsCoordinateReferenceSystem::createFromWkt -- theWkt is
> uninitialised, operation failed
> Warning: QPainter::end: Painter not active, aborted
> Warning: QPainter::begin: Cannot paint on a null pixmap
> Warning: QPainter::setFont: Painter not active
> Warning: QPainter::end: Painter not active, aborted
> Warning: QPixmap::scaled: Pixmap is a null pixmap
>
>  *** caught segfault ***
> address 0x7fc3bcdf4000, cause 'memory not mapped'
>
> Possible actions:
> 1: abort (with core dump, if enabled)
> 2: normal R exit
> 3: exit R without saving workspace
> 4: exit R saving workspace
> Selection: Exception in thread Thread-1:
> Traceback (most recent call last):
>  File "/usr/lib/python2.5/threading.py", line 486, in __bootstrap_inner
>    self.run()
>  File "/usr/lib/python2.5/threading.py", line 446, in run
>    self.__target(*self.__args, **self.__kwargs)
>  File "/usr/lib/python2.5/site-packages/rpy.py", line 226, in r_eventloop
>    _r_lock.release()
> error: release unlocked lock

 But does it still segfault if you don't have any R plugins in your
plugin folders? By that I mean not just loaded but disabled, but not
even there at all? You need to delete any R plugin folders from your
plugin folder (or maybe make them unreadable).

 What I thought was weird was getting an R error message when I didnt
have any R plugins enabled. This was because the plugin installer was
loading all plugins (even disabled ones) to see if it could possibly
load them if asked. Hence any segfault caused an R segfault message,
because R was trapping segfaults.

 You might have just found a segfault problem in Qgis itself, no R involved!

 Barry