I’m not sure what has changed, but traceplot(fit) is now throwing an error where it wasn’t before (and crashing R!). Any ideas? This code works in R64 but not in R32!

Windows 10

R version 3.5.0

RStudio 1.1.444

rstan 2.17.3

```
stan_pars <- c('medb0raw', 'medd1raw', 'slowb0raw', 'slowd1raw',
'chem1fast', 'chem1med', 'chem1slow', 'chem2fast', 'chem2med', 'chem2slow')
print(fit, stan_pars)
stan_diag(fit)
stan_par(fit, stan_pars[[2]]) # look at misbehaving parameters
# pairs plot to show correlation
temp <- pairs(fit, pars=stan_pars)
# diagnostic plots to check convergence
some_vars <- stan_pars
temp <- traceplot(fit, pars=some_vars)
Error: `predicate` must be a closure or function pointer
```