Question

I have just tried to install the DirectedGraphPlugin on our wiki. It appeared to install fine but when I try to view one of the example scripts on a test page I get the error:

DirectedGraph Error (2):

If I look in the logs I can't seem to find anything regarding this error, except in the apache log it says:

view: use of uninitialised value in concatenation (.) or stringe at (twiki home directory path)/lib/TWiki/Plugins/DirectedGraphPlugin.pm line\446

Looking at that line this log entry seems to be refering just to the correct error message (the bit after the ':' in DirectedGraph Error (2):) being displayed.

Has anyone any input at all on what might be causing this? I did have a problem finding the correct module to install for Perl module Digest::MD5 as mentioned in the installation instructions, as this module seems to have since been superceded by the lastest perl release.

Environment

-- JensPagotto - 23 Oct 2006

Answer

If you answer a question - or someone answered one of your questions - please remember to edit the page and set the status to answered. The status selector is below the edit box.

Here is what to check:

Make sure the cgi process (usually the web server) can write to all of pub. Sometimes a "chown -R www-data:www-data pub" dosn't hurt. Also check permisions in /var/lib/twiki/data and /var/lib/twiki/log. Next look for correct paths in /usr/share/perl5/TWiki/Plugins/DirectedGraphPlugin.pm (in Debian) or wherever it is. Spcifically the $dotHelperPath variable.

-- ClifCox - 19 Nov 2006

I'm getting this error as well, on a fresh installation of TWiki 4.2.3. Doing a chown -R _www:_www /Library/WebServer/Documents didn't help. However, I did fix the paths in DirectedGraphPlugin.pm.

It turns out that the configure section devoted to DirectedGraphPlugin is not clear. It asks for the path to the GraphViz and ImageMagick executables (not the full filename), and the path to the 'tools' directory, and from the beginning, these fields are colored green.

It would be good to change these to ask for the full pathname, so that the color of these fields could be red if the executables or the helper are not found. Also, the error message 'Directed Graph Error 2' really should be 'file not found' error.

-- CharlesHowes - 07 Oct 2008

You get the same "Error 2" if the pub dir for the web does not exist.

-- TWikiGuest - 10 Nov 2008