The GraphViz extension uses wfShellExec() to invoke the "dot" command. Sometime in the last month or so, on my Ubuntu 14.04 installation, the command started failing with: Warning: Could not load "/usr/lib/graphviz/libgvplugin_gd.so.6" - file not found
The file does exist and the dot command runs fine from a shell session.
I found that by eliminating the ulimit -v option from ulimit4.sh, which wfShellExec() invokes, the problem goes away.
The -v limit is 102400 on my installation (so 100Mb). I find it hard to believe that dot actually needs that much virtual memory.
Suggestions on how to proceed with debug would be much appreciated.
Thanks, Keith Welter