Try autowp/arduino-mcp2515 as custom library.

Author: BlueAndi

.github/workflows/testCompile.yml

@@ -27,10 +27,18 @@ jobs:
           path: CustomLibrary # must contain string "Custom"
           # No need to put "Custom" library in the required-libraries list
 
+      - name: Checkout autowp-mcp2515 as custom library
+        uses: actions/checkout@v4
+        with:
+          repository: autowp/arduino-mcp2515
+          ref: master
+          path: CustomLibrary_autowp-mcp2515 # must contain string "Custom"
+          # No need to put "Custom" library in the required-libraries list
+
       - name: Compile all examples
         uses: ArminJo/arduino-test-compile@v3
         with:
           sketch-names: "*.ino"
           sketch-names-find-start: examples/
-          required-libraries: mcp_can@1.5.1, autowp-mcp2515
+          required-libraries: mcp_can@1.5.1
           debug-install: true