attempt to fix windows CI failure

Author: katrinabrock

tests/testthat/test-opencl.R

@@ -3,6 +3,9 @@ context("opencl")
 set_cmdstan_path()
 fit <- testing_fit("bernoulli", method = "sample", seed = 123, chains = 1)
 
+runner_temp <- Sys.getenv('RUNNER_TEMP')
+if(runner_temp != "") Sys.setenv(TMPDIR=runner_temp)
+
 test_that("all methods error when opencl_ids is used with non OpenCL model", {
   stan_file <- testing_stan_file("bernoulli")
   exe_file <- tempfile(pattern = "bernoulli-")