Install fallback compiler first

src/mpsd_software_manager/spack.py

@@ -586,14 +586,14 @@ def install_toolchain_compiler(spack_environment: str) -> dict[str, dict[str, st
                 )
             elif line.startswith("toolchain_gcc_package"):
                 gcc_package = line.split('"')[1]
-        compilers["default"] = {
-            "name": intel_compiler,
-            "package": f"{intel_package}%{gcc_package}",
-        }
         compilers["fallback"] = {
             "name": gcc_package,
             "package": f"{gcc_package}%{Config().system_compiler}",
         }
+        compilers["default"] = {
+            "name": intel_compiler,
+            "package": f"{intel_package}%{gcc_package}",
+        }
 
     logger.debug("Required toolchain compiler: %s", compilers)