processx error with ulam()

[jswesner]

processx error with ulam()

[rmcelreath]

The problem is not my package, but that cmdstanr doesn't have permission to write to the directory. So it couldn't write the compiled model to disk. Seems like other people have had this problem and there is an option in cmdstanr to change the path? This is what I found by searching a bit: https://discourse.mc-stan.org/t/permissions-error-running-brms-on-windows-with-cmdstanr-backend/28429

[rmcelreath]

Sorry I can't be of more help. But yes, if you can get cmdstanr to work on, then ulam() should work. ulam() just builds Stan code and passes it to cmdstanr for the hard part.

[jswesner]

Thank you. I tried changing the path as suggested there with no luck. But since the issue is in cmdstanr and permissions, I'll see if I can resolve it within cmdstanr first.

[torkar]

Remember that you need to compile cmdstan etc. again with a new path.

[jswesner]

I've found a workaround by using rstan as the backend instead of cmdstan with set_ulam_cmdstan(F). In case it was confusing to anyone else, I first tried to use rstan within the ulam() function: ulam(model...., cmdstan = F). But this did not work. After reading the help closer, I needed to use set_ulam_cmdstan(F) first outside of the ulam() model. Then running the ulam() model worked fine.