Updated to simplify logic

conans/client/conf/detect.py

@@ -156,14 +156,14 @@ def _get_default_compiler(output):
         command = cc or cxx
         if "gcc" in command:
             gcc = _gcc_compiler(output, command)
-            if gcc is not None:
-                return gcc
-            if platform.system() == "Darwin":
+            if platform.system() == "Darwin" and gcc is None:
                 output.warn(
                     "%s detected as a frontend using apple-clang, skipping it to use native apple-clang" % command
                 )
-                # using clang instead
+                # Fallback to use clang instead
                 command = "clang"
+            else:
+                return gcc
         if "clang" in command.lower():
             return _clang_compiler(output, command)
         if platform.system() == "SunOS" and command.lower() == "cc":