2016-06-09 15:48:41 +0100 asked a question RuntimeError when starting pari/library not found Hello, I am using a binary distribution of sage 7.1 for debian jessie and "installed" it to /opt. Now, when I want to use pari, I get a runtime error:  sage: %gp   --> Switching to PARI/GP interpreter <--   pari: sqrt(4)   RuntimeError: unable to start pari  The full backtrace can be found here: paste.kde.org/pvqeoh3ve however, the following works:  LD_LIBRARY_PATH=/opt/sage-7.1/local/lib sage  It seems that sage is unable to find that library when starting pari. Setting SAGE_ROOT does not help. Did I miss some configuration file to set the library path for sage?