Hi all! I am trying use OpenCL to run `cmdstanr`

models with an AMD Radeon Pro 580 GPU. I am using Mac OSX 10.15.7 (Catalina).

I successfully installed cmdstan and `check_cmdstan_toolchain()`

returns that it is set up correctly.

However, when I try to fit an example model, it fails. Here is a simple example (from Running Stan on the GPU with OpenCL • cmdstanr):

```
data {
int<lower=1> k;
int<lower=0> n;
matrix[n, k] X;
array[n] int y;
}
parameters {
vector[k] beta;
real alpha;
}
model {
target += std_normal_lpdf(beta);
target += std_normal_lpdf(alpha);
target += bernoulli_logit_glm_lpmf(y | X, alpha, beta);
}
```

And some generated data:

```
# Generate some fake data
n <- 250000
k <- 20
X <- matrix(rnorm(n * k), ncol = k)
y <- rbinom(n, size = 1, prob = plogis(3 * X[,1] - 2 * X[,2] + 1))
mdata <- list(k = k, n = n, y = y, X = X)
```

It runs just fine on the CPU using this code:

```
# no OpenCL version
mod <- cmdstan_model("bernoulli_logit_glm.stan")
fit_cpu <- mod$sample(data = mdata, chains = 4, parallel_chains = 4, refresh = 0)
```

However, when I try to run using OpenCL, it fails:

```
mod_cl <- cmdstan_model("bernoulli_logit_glm.stan",
cpp_options = list(stan_opencl = TRUE), force_recompile=TRUE)
fit_cl <- mod_cl$sample(data = mdata, chains = 4, parallel_chains = 4,
opencl_ids = c(0, 1), refresh = 0)
```

This is the output I get:

```
# Running MCMC with 4 parallel chains...
# Chain 1 cvmsBuildComputeProgram No CVMS service
# Chain 1 Unrecoverable error evaluating the log probability at the initial value.
# Chain 1 Exception: compile_kernel: calculate : Unknown error -11 (in '/var/folders/ch/qb5870nx4r31bjqvyjr656pr0000gp/T/Rtmph5Fw5s/model-73092c28f33c.stan', line 14, column 2 to column 57)
# Chain 2 cvmsBuildComputeProgram No CVMS service
# Chain 2 Unrecoverable error evaluating the log probability at the initial value.
# Chain 2 Exception: compile_kernel: calculate : Unknown error -11 (in '/var/folders/ch/qb5870nx4r31bjqvyjr656pr0000gp/T/Rtmph5Fw5s/model-73092c28f33c.stan', line 14, column 2 to column 57)
# Chain 3 cvmsBuildComputeProgram No CVMS service
# Chain 3 Unrecoverable error evaluating the log probability at the initial value.
# Chain 3 Exception: compile_kernel: calculate : Unknown error -11 (in '/var/folders/ch/qb5870nx4r31bjqvyjr656pr0000gp/T/Rtmph5Fw5s/model-73092c28f33c.stan', line 14, column 2 to column 57)
# Chain 4 cvmsBuildComputeProgram No CVMS service
# Chain 4 Unrecoverable error evaluating the log probability at the initial value.
# Chain 4 Exception: compile_kernel: calculate : Unknown error -11 (in '/var/folders/ch/qb5870nx4r31bjqvyjr656pr0000gp/T/Rtmph5Fw5s/model-73092c28f33c.stan', line 14, column 2 to column 57)
# Warning: Chain 1 finished unexpectedly!
# Warning: Chain 2 finished unexpectedly!
# Warning: Chain 3 finished unexpectedly!
# Warning: Chain 4 finished unexpectedly!
# Warning: Use read_cmdstan_csv() to read the results of the failed chains.
# Warning messages:
# 1: All chains finished unexpectedly! Use the $output(chain_id) method for more information.
# 2: No chains finished successfully. Unable to retrieve the fit.
```

When I google “cvmsBuildComputeProgram No CVMS service” I get no results so I am at a loss. I know I’m specifying the GPU device ID correctly because I checked the platform and device ID, and if I set other combos of platform & device IDs I get errors saying the devices don’t exist. Anyone have a similar issue or fix? Thanks in advance!!