fix argument expansion in github actions and build.bat

.github/workflows/builds.yml

@@ -31,7 +31,7 @@ jobs:
         shell: cmd
         run: |
           call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" x64
-          call build %${{ matrix.target }}% %${{ matrix.compiler }}% %${{ matrix.mode }}% || exit /b 1
+          call build "${{ matrix.target }}" "${{ matrix.compiler }}" "${{ matrix.mode }}" || exit /b 1
 
   run-torture:
     runs-on: windows-2022

build.bat

@@ -27,7 +27,7 @@ cd /D "%~dp0"
 :: - `spall`: enable spall profiling support
 
 :: --- Unpack Arguments -------------------------------------------------------
-for %%a in (%*) do set "%%a=1"
+for %%a in (%*) do set "%%~a=1"
 if not "%msvc%"=="1" if not "%clang%"=="1" set msvc=1
 if not "%release%"=="1" set debug=1
 if "%debug%"=="1"   set release=0 && echo [debug mode]