I was following the 1st tutorial at
In ElmerPost, bring up a colorscale, and set the Colorscale Style to vertical. This will result in a segfault.
The problem is at elmerpost/src/visuals/colscale.c at line 170. The call to "XTextWidth( CurrentXFont,..." segfaults since CurrentXFont is a null pointer.
Choosing a font before changing the colorscale to vertical works around this problem.