Disable all snippet grading but continue inline grading

I want to turn off all evaluation of a snippet but keep inline evaluation with \Sexpr

. Installation eval

globally on FALSE

like this

  \documentclass{article}

   \begin{document}

   <<setup, include=FALSE>>=
   opts_chunk$set(eval= FALSE)
   @

   \Sexpr{"is not displayed"} bummer.
   \end{document}

      

        
        
        
      

    

also affects \Sexpr

.

ps: I've searched all subsets of [knitr], \ Sexpr, eval. I just hope the formatting is correct.

ps: I don't want to set eval to 1.