I noticed that my model which includes inference on P-dimensional correlation matrix kept crashing in simple cases. Minimal example below: as soon as I sample with P=1, Stan run crashes for me without a warning.

Not sure if it’s just me or is it not possible to have a 1x1 corr_matrix? I think it’s obviously useful in case you want to have a single Stan program that can cover both univariate and multivariate cases.

```
data {
int<lower=1> P;
}
parameters {
corr_matrix[P] Omega;
}
```