[Bug 414027] Re: dotty hangs with cpu spin for "apt-cache dotty monodevelop" graph

[Martin Olsson]

This also affects more basic packages like gcalctool, acl, linux-image,
binutils etc. In fact I can't find a single package where it actually
pops up a rendered a graph within reasonable time. Our definitions of
reasonable might be different though :-)

btw, I'm seeing this:

$ cat firefox.txt | g '\->' | wc -l
10471
$ cat firefox.txt | g shape | wc -l
2505

...and I wonder, is it realistic for graphviz to handle 2500 nodes with
10k edges?

I was thinking, if graphviz could provide some progress information
during layout then dotty could show a UI progress bar with a cancel
button. But, in reality the time dotty takes to render these graphs is
so long that a progress bar doesn't really help a lot. Indeed, it makes
me suspect that maybe we're dealing with a simpler bug that makes
graphviz go into an infinite CPU spin loop?

If it's verified that the firefox dep graph (and indeed many other
packages) is indeed too heavy for graphviz and this is not a graphviz
bug, it would make sense to A) investigate if some other graph layout
(other than "dot") can be used within graphviz to make it faster, or B)
use some other graph library instead of using graphviz, or C) have apt-
cache prune the graph when it gets too complicated (either by not
showing all kinds of edges like conflicting/recommended etc) or by
simply not showing all dependencies (i.e. maybe just first level or
first+second level dependencies).

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to graphviz in Ubuntu.
https://bugs.launchpad.net/bugs/414027

Title:
  dotty hangs with cpu spin for "apt-cache dotty monodevelop" graph

Status in “graphviz” package in Ubuntu:
  Confirmed

Bug description:
  This works just fine on Ubuntu karmic:
  apt-cache dotty binutils | dotty -

  These ones gets stuck inside a CPU spin and never finishes though:
  apt-cache dotty gedit | dotty -
  apt-cache dotty firefox | dotty -
  apt-cache dotty monodevelop | dotty -

  The first part (e.g. "apt-cache dotty firefox") finishes just fine so
  the bug must be in dotty or later on in the chain.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/graphviz/+bug/414027/+subscriptions