fuel.eval: using a local fuel-eval-error symbol.  Fixes #142.
fuel.eval: using a local fuel-eval-error symbol.  Fixes #142.

erg/factor,mcandre/factor,mcandre/factor,erg/factor,erg/factor,erg/factor,erg/factor,mcandre/factor,mcandre/factor,mcandre/factor,erg/factor,mcandre/factor,mcandre/factor,erg/factor