From 4384223951b3561cc5451ecf2f77c3ed55c59186 Mon Sep 17 00:00:00 2001
From: Rangi <35663410+Rangi42@users.noreply.github.com>
Date: Thu, 30 Jul 2026 12:59:53 -0400
Subject: [PATCH] CI testing in Cygwin 64-bit now uses CMake and runs external
 tests (#2037)

---
 .github/workflows/testing.yml | 54 +++++++++++++++++++++++++++++------
 include/platform.hpp          |  4 +--
 2 files changed, 47 insertions(+), 11 deletions(-)

diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 63e2faf1..3b06d466 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -333,12 +333,7 @@ jobs:
   cygwin:
     strategy:
       matrix:
-        bits: [32, 64]
-        include:
-          - bits: 32
-            arch: x86
-          - bits: 64
-            arch: x86_64
+        arch: [x86, x86_64]
       fail-fast: false
     runs-on: windows-2022
     timeout-minutes: 30
@@ -358,22 +353,63 @@ jobs:
           platform: ${{ matrix.arch }}
           packages: >-
             bison
+            cmake
             gcc-g++
             git
             libpng-devel
             make
+            ninja
             pkg-config
-      - name: Build
+            python3
+            python-imaging
+      - name: Build using Make
+        if: matrix.arch == 'x86'
         run: | # Cygwin doesn't support `make develop` sanitizers ASan or UBSan, so we don't use it.
           make -k -j "$(getconf _NPROCESSORS_ONLN)" Q=
-      - name: Install
+      - name: Install using Make
+        if: matrix.arch == 'x86'
         run: |
           make install Q=
           type rgbasm rgblink rgbfix rgbgfx
           man -w 1 rgbasm rgblink rgbfix rgbgfx
-      - name: Run tests
+      - name: Build using CMake
+        if: matrix.arch == 'x86_64'
+        run: | # Cygwin doesn't support `--preset develop` sanitizers ASan or UBSan, so we disable them.
+          cmake -B build -G Ninja --preset develop -DSANITIZERS=OFF
+          cmake --build build -- -k 0
+      - name: Install using CMake
+        if: matrix.arch == 'x86_64'
+        run: |
+          cmake --install build --verbose
+          type rgbasm rgblink rgbfix rgbgfx
+          man -w 1 rgbasm rgblink rgbfix rgbgfx
+      - name: Compute test dependency cache params
+        id: test-deps-cache-params
+        run: |
+          paths=$(test/external/fetch-repos.sh --get-paths)
+          hash=$(test/external/fetch-repos.sh --get-hash)
+          tee -a <<<"paths=\"${paths//,/\\n}\"" $GITHUB_OUTPUT
+          tee -a <<<"hash=${hash%-}" $GITHUB_OUTPUT
+      - name: Check test dependency repositories cache
+        id: test-deps-cache
+        uses: actions/cache@v5
+        with:
+          path: ${{ fromJSON(steps.test-deps-cache-params.outputs.paths) }}
+          key: cygwin-${{ matrix.bits }}-${{ steps.test-deps-cache-params.outputs.hash }}
+      - name: Fetch test dependency repositories
+        if: steps.test-deps-cache.outputs.cache-hit != 'true'
+        continue-on-error: true
+        run: |
+          test/external/fetch-repos.sh
+      - name: Run tests using our script
+        if: matrix.arch == 'x86'
         run: | # 32-bit Cygwin's `git` 2.38 doesn't support `git clone --revision`, so we don't fetch/run external tests.
           test/run-tests.sh --os cygwin --only-internal --jobs "$(getconf _NPROCESSORS_ONLN)"
+      - name: Run tests using CTest
+        if: matrix.arch == 'x86_64'
+        run: | # The external test repo `libbet` uses `py -3` instead of `python3` if `COMSPEC` is defined, so we clear it.
+          unset COMSPEC
+          ctest --test-dir build --schedule-random
       - name: Use Windows git location in the PATH
         shell: pwsh
         run: | # Prevents the `actions/checkout` post-job cleanup from using Cygwin's git binary
diff --git a/include/platform.hpp b/include/platform.hpp
index 7c20c9c1..fd5156f6 100644
--- a/include/platform.hpp
+++ b/include/platform.hpp
@@ -61,8 +61,8 @@
 	#define ftell _ftelli64
 #endif
 
-// MingGW and Cygwin need POSIX functions which are not standard C explicitly enabled,
-#if defined(__MINGW32__) || defined(__CYGWIN__)
+// MingGW and Cygwin may need POSIX functions which are not standard C explicitly enabled
+#if (defined(__MINGW32__) || defined(__CYGWIN__)) && !defined(_POSIX_C_SOURCE)
 	#define _POSIX_C_SOURCE 200809L
 #endif