--- a/mesonbuild/coredata.py
+++ b/mesonbuild/coredata.py
@@ -483,7 +483,6 @@ class CoreData:
             return value
         if option.endswith('dir') and value.is_absolute() and \
            option not in builtin_dir_noprefix_options:
-            # Value must be a subdir of the prefix
             # commonpath will always return a path in the native format, so we
             # must use pathlib.PurePath to do the same conversion before
             # comparing.
@@ -495,7 +494,7 @@ class CoreData:
             try:
                 value = value.relative_to(prefix)
             except ValueError:
-                raise MesonException(msg.format(option, value, prefix))
+                pass
             if '..' in str(value):
                 raise MesonException(msg.format(option, value, prefix))
         return value.as_posix()