From 700cb62fa1d48d1d35547bb7690f8e6de6c2b93e Mon Sep 17 00:00:00 2001
From: Andrew Johnson <andrew.johnson@arjohnsonau.com>
Date: Wed, 22 May 2024 21:06:33 +0300
Subject: [PATCH 1/4] Add CMDSTANR_USE_RTOOLS envvar to use stock rtools

---
 .github/workflows/R-CMD-check.yaml |  6 ++++++
 R/install.R                        | 10 ++++++++--
 R/utils.R                          |  2 +-
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index c43b91e6..37000a84 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -42,6 +42,12 @@ jobs:
           echo "CMDSTAN_PATH=${HOME}/.cmdstan" >> $GITHUB_ENV
         shell: bash
 
+      - name: Use stock RTools for Windows R-Devel
+        if: ${{ matrix.config.os == 'windows-latest' && matrix.config.r == 'devel' }}
+        run: |
+          echo "CMDSTANR_USE_RTOOLS=TRUE" >> $GITHUB_ENV
+        shell: bash
+
       - uses: n1hility/cancel-previous-runs@v3
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/R/install.R b/R/install.R
index 942bf77c..3a430a4e 100644
--- a/R/install.R
+++ b/R/install.R
@@ -635,6 +635,9 @@ check_rtools4x_windows_toolchain <- function(fix = FALSE, quiet = FALSE) {
       call. = FALSE
     )
   }
+  if (Sys.getenv("CMDSTANR_USE_RTOOLS") != "") {
+    return(invisible(NULL))
+  }
   if (!is_toolchain_installed(app = "g++", path = toolchain_path) ||
       !is_toolchain_installed(app = "mingw32-make", path = toolchain_path)) {
     if (!fix) {
@@ -844,8 +847,11 @@ toolchain_PATH_env_var <- function() {
 }
 
 rtools4x_toolchain_path <- function() {
-  c_runtime <- ifelse(is_ucrt_toolchain(), "ucrt64", "mingw64")
-  repair_path(file.path(rtools4x_home_path(), c_runtime, "bin"))
+  toolchain <- ifelse(is_ucrt_toolchain(), "ucrt64", "mingw64")
+  if (Sys.getenv("CMDSTANR_USE_RTOOLS") != "") {
+    toolchain <- "x86_64-w64-mingw32.static.posix"
+  }
+  repair_path(file.path(rtools4x_home_path(), toolchain, "bin"))
 }
 
 rtools4x_version <- function() {
diff --git a/R/utils.R b/R/utils.R
index b41287ee..d03184ab 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -85,7 +85,7 @@ is_rosetta2 <- function() {
 
 # Returns the type of make command to use to compile depending on the OS
 make_cmd <- function() {
-  if (os_is_windows() && !os_is_wsl()) {
+  if (os_is_windows() && !os_is_wsl() && (Sys.getenv("CMDSTANR_USE_RTOOLS") == "")) {
     "mingw32-make.exe"
   } else {
     "make"

From 2ab63d8b32744b0fa1cbfd663c86af3fe132b736 Mon Sep 17 00:00:00 2001
From: Andrew Johnson <andrew.johnson@arjohnsonau.com>
Date: Wed, 22 May 2024 21:18:15 +0300
Subject: [PATCH 2/4] CI needs 2.35 RC for stock rtools

---
 .github/workflows/R-CMD-check.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index 37000a84..e2fe66f5 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -69,6 +69,11 @@ jobs:
       - name: Install cmdstan
         run: |
           cmdstanr::check_cmdstan_toolchain(fix = TRUE)
+          if (Sys.getenv("CMDSTANR_USE_RTOOLS") == "TRUE") {
+            cmdstanr::install_cmdstan(cores = 2, version = "2.35.0-rc2")
+          } else {
+            cmdstanr::install_cmdstan(cores = 2)
+          }
           cmdstanr::install_cmdstan(cores = 2)
         shell: Rscript {0}
 

From 0c2cc823d064567728e2b6024f1fb80869c7bf38 Mon Sep 17 00:00:00 2001
From: Andrew Johnson <andrew.johnson@arjohnsonau.com>
Date: Wed, 22 May 2024 21:27:57 +0300
Subject: [PATCH 3/4] Typo

---
 .github/workflows/R-CMD-check.yaml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index e2fe66f5..5b2db711 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -74,7 +74,6 @@ jobs:
           } else {
             cmdstanr::install_cmdstan(cores = 2)
           }
-          cmdstanr::install_cmdstan(cores = 2)
         shell: Rscript {0}
 
       - name: Session info

From 884ea8522d0579fe3aa2154499af2d084bb556bf Mon Sep 17 00:00:00 2001
From: Andrew Johnson <andrew.johnson@arjohnsonau.com>
Date: Wed, 22 May 2024 23:03:21 +0300
Subject: [PATCH 4/4] Rtools make needs diff path handling

---
 R/model.R                     | 2 +-
 tests/testthat/test-install.R | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/R/model.R b/R/model.R
index 8db71a17..c3ef104c 100644
--- a/R/model.R
+++ b/R/model.R
@@ -672,7 +672,7 @@ compile <- function(quiet = TRUE,
       ),
       run_log <- wsl_compatible_run(
         command = make_cmd(),
-        args = c(wsl_safe_path(tmp_exe),
+        args = c(wsl_safe_path(repair_path(tmp_exe)),
                 cpp_options_to_compile_flags(cpp_options),
                 stancflags_val),
         wd = cmdstan_path(),
diff --git a/tests/testthat/test-install.R b/tests/testthat/test-install.R
index 211a19c3..5d415543 100644
--- a/tests/testthat/test-install.R
+++ b/tests/testthat/test-install.R
@@ -1,4 +1,6 @@
 context("install")
+# Current tests need CmdStan 2.35 for stock rtools, but is not yet released
+skip_if(Sys.getenv("CMDSTANR_USE_RTOOLS") != "")
 
 cmdstan_test_tarball_url <- Sys.getenv("CMDSTAN_TEST_TARBALL_URL")
 if (!nzchar(cmdstan_test_tarball_url)) {