Combination of $$ and bmatrix does not work?

[oscargus]

It seems like bmatrix does not work when combined with $$. I have no understanding of why, but $$ works and bmatrix works when combined with .. math::.

The problem shows as (linsolve):

(I'm working on a new PR for SymPy where I have replaced bmatrix with array here, so it may go away if it is merged.)