Cantor 17.12 crashes working with R and Sage backends and is very slow with some other ones on Arch Linux.

Alexander Semke alexander.semke at
Sat Jan 13 10:39:55 UTC 2018

Hello Fernando,

thank you for your warm words about KDE and Cantor :-)

The connection to and the initialization of a backend process takes some 
time. The times are different for different backends.
Your observations about the long evaluation times for the first 
expression and almost instant evaluation of the subsequent expressions
is because of the recent improvement that was done in 17.12. Previously, 
the initialization was done during the creation of a new session.
So, when opening a project file the user had to wait until the 
initialization is done even in cases where he/she doesn't plan to modify 
the worksheet at all.
This was changed. The creation of a new session or opening of saved 
project files is much faster now and the initialization of the backend 
process is
postponed to the point when the user really asks Cantor to evaluate 

The recommended versions for R and Sage are missing, yes. But those are 
minor issues compared to the crashes you have. Let's have a look at them 
Which versions of Maxima and Sage are you using? Any chance to install 
the debuginfo package for Cantor and to try again? Without the debug symbols
the crash dumps are not really useful...

Connection to R is broken, the fix for this is "work in progress" at the 


P.S.: @kde-edu moderators: no need to approve my previous email 
containing all the screenshots again.

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