create build dir

.github/workflows/build.yml

@@ -41,6 +41,11 @@ jobs:
           tar -xf llvm-mingw.tar.xz
           mv llvm-mingw-* llvm-mingw
     
+      - name: Create Build Environment
+        # Some projects don't allow in-source building, so create a separate build directory
+        # We'll use this as our working directory for all subsequent commands
+        run: cmake -E make_directory ${{github.workspace}}/build
+
       - name: Configure CMake
         working-directory: ${{github.workspace}}/build
         run: |