Error: 'makevars_user' is not an exported object from 'namespace:withr'

[shashank.lal]

i'm bit new to R and facing some issues while getting the CLV by following the below link
https://medium.com/ordergroove-engineering/every-customer-counts-52aa70e4f85

I'm getting below error
Error: 'makevars_user' is not an exported object from 'namespace:withr'

while fitting the model
model_fit <- stan(file = "full_clv.stan",
data = model_data,
chains = 4,
iter = 1000)

I'm using R Version-3.6.1 and Rstudio Version 1.3.1056

Any help would be very helpful. Please let me know in case any more details are required from my end.

[shashank.lal]

Didn't realized that withr is implicitly called from rstan, removing rstan and withr and then installing them back in reverse sequence fix the issue.