From this ask.sagemath.org question.

plot(x,0,2,gridlines=([sqrt(2)],[]))

blows up.

The fix is probably to make sure that symbolic input with a n() method passes something right to matplotlib, which of course cannot handle sqrt(2). Possibly beginner ticket.

Note: A beginner who is interested in working on this ticket can skip down to comment:13.

CC: @jasongrout @sagetrac-dsm

Component: graphics

Author: Atte Niemi

Branch/Commit: 702d272

Reviewer: Dave Morris

Issue created by migration from https://trac.sagemath.org/ticket/10980