From 3443a9440714e7e3229b07f6641a8c56bc43a935 Mon Sep 17 00:00:00 2001
From: past-due <30942300+past-due@users.noreply.github.com>
Date: Tue, 8 Dec 2020 13:21:57 -0500
Subject: [PATCH] GitHub Actions: Cache dependencies

---
 .github/workflows/CI.yml | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index dd5cba41..5bbf9bf9 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -41,11 +41,33 @@ jobs:
         # See: https://github.com/actions/virtual-environments/tree/main/images/macos
         run: sudo xcode-select -switch /Applications/Xcode_12.2.app/Contents/Developer
 
-      - name: Create Build Logs Dir
+      - name: Prep
+        id: prep
         run: |
+          echo "Create Build Logs Dir"
           mkdir -p "${HOME}/build_logs"
+          echo "Get Xcode version info"
+          XCODE_VERSION="$(xcodebuild -version)"
+          echo "${XCODE_VERSION}"
+          XCODE_VERSION="$(echo "${XCODE_VERSION}" | tr '\t\r\n ' '_')"
+          echo "${XCODE_VERSION}"
+          echo "::set-output name=XCODE_VERSION::${XCODE_VERSION}"
+
+      - name: Cache Dependencies
+        id: cache-dependencies
+        if: success() && !(github.event_name == 'push' && contains(github.ref, 'refs/tags/')) # never cache dependencies for pushed tags
+        uses: actions/cache@v2
+        with:
+          path: External/build/
+          key: ${{ runner.os }}-${{ steps.prep.outputs.XCODE_VERSION }}-${{ matrix.platform }}-${{ hashFiles('fetchDependencies','ExternalRevisions/**','ExternalDependencies.xcodeproj/**','Scripts/**') }}
+
+      - name: Fetch Dependencies (Use Built Cache)
+        if: steps.cache-dependencies.outputs.cache-hit == 'true'
+        run: |
+          ./fetchDependencies -v --no-parallel-build --none
 
       - name: Fetch Dependencies
+        if: steps.cache-dependencies.outputs.cache-hit != 'true'
         run: |
           ./fetchDependencies -v --no-parallel-build --${{ matrix.platform }}