Test alt config

R/model.R

@@ -651,6 +651,16 @@ compile <- function(quiet = TRUE,
       expose_stan_functions(self$functions, !quiet)
     }
 
+    env_vars <- "current"
+    if (os_is_linux()) {
+      env_vars <- c(env_vars, "CXXFLAGS"="-fPIC")
+    }
+    if (os_is_windows() && is_ucrt_toolchain()) {
+      cxx <- "x86_64-w64-mingw32.static.posix-g++"
+      cc <- "x86_64-w64-mingw32.static.posix-gcc"
+      env_vars <- c(env_vars, "CXX"=cxx, "CC"=cc)
+    }
+
     withr::with_path(
       c(
         toolchain_PATH_env_var(),
@@ -662,7 +672,7 @@ compile <- function(quiet = TRUE,
                 cpp_options_to_compile_flags(c(cpp_options, list("KEEP_OBJECT"="true"))),
                 stancflags_val),
         wd = cmdstan_path(),
-        env = c("current", "CXXFLAGS"="-fPIC"),
+        env = env_vars,
         echo = !quiet || is_verbose_mode(),
         echo_cmd = is_verbose_mode(),
         spinner = quiet && rlang::is_interactive() && !identical(Sys.getenv("IN_PKGDOWN"), "true"),

R/utils.R

@@ -741,7 +741,7 @@ with_cmdstan_flags <- function(expr) {
   libs <- c("LDLIBS", "LIBSUNDIALS", "TBB_TARGETS", "LDFLAGS_TBB")
   libs <- paste(sapply(libs, get_cmdstan_flags), collapse = " ")
   if (.Platform$OS.type == "windows") {
-    libs <- paste(libs, "-fopenmp -lstdc++")
+    libs <- paste(libs, "-fopenmp")
   }
   lib_paths <- c("/stan/lib/stan_math/lib/tbb/",
                  "/stan/lib/stan_math/lib/sundials_6.1.1/lib/")
@@ -1061,3 +1061,11 @@ expose_stan_functions <- function(function_env, global = FALSE, verbose = FALSE)
   }
   invisible(NULL)
 }
+
+get_r_config <- function(config_name) {
+  system2(
+      command = file.path(R.home(component = "bin"), "R"),
+      args = c("CMD", "config", config_name),
+      stdout = TRUE
+  )
+}