Disable canonicalization in brms compiling with cmdstan(r)

I have begun to get parsing errors when using various versions of Cmdstan (2.29.1 and beyond) with brms, along these lines:

     1:  Running bin/stanc /tmp/RtmpTWcHVn/model_ba9a4a552b982135385bbfe7ea95274c.stan \
     2:    --auto-format '--canonicalize=deprecations,braces,parentheses'
     3:  // generated with brms 2.18.8

Expected "functions {" or "data {" or "transformed data {" or "parameters {" or "transformed parameters {" or "model {" or "generated quantities {". 

This appears to be the updating / formatting discussed by Section 34.5 of the Stan User’s Guide, but I would rather just disable it. Is disabling these checks an option, perhaps with a flag in stan_model_args=list(stanc_options ...)?

This looks like a bug actually, can you share a reproducible example?

I agree, this seems like the generated code from brms can not compile. It does not have anything to do with the the auto-formatter or canonicalizer.

Sure I will work on that, thanks. I seemed to solve it in an interactive session by removing cmdstan versions above 2.29.1 and letting it default back to a previous install of the latter, but the error came back when executing at the command line. I will try to figure out what makes it consistently reproducible.