# chromatic polynomial graph with loops

Since there are no proper colorings of graphs with loops, their chromatic polynomial should be zero.

SageMath 8.6 however seems to ignore the loops and returns a nonzero chromatic polynomial for the graph on one vertex with one loop edge.

```
sage: Graph([[1, 1]], multiedges=True, loops=True).chromatic_polynomial()
x
```

This indeed looks like a bug. Thanks for reporting!

Would you like to open a ticket for it on the Sage Trac server?

Would you like to suggest a fix? The relevant file is

(If not, I can take care of it.)

Now tracked at