Red Car Property: Baguette Or Mushroom?

Photo: Diane Edwardson, December 15, 2015.  Looking more like a baguette that's seen better days, it appears bugs have eaten the mushroom from the inside out - leaving the trail of frass on the outside.  (Click on photo to enlarge.)

I noticed this mushroom growing in one of the few Eucalyptus trees that have not yet succumbed to drought/disease/infestation on the north end of the Red Car