add more warning details

spacy/cli/init_config.py

@@ -67,7 +67,6 @@ def init_config_cli(
             "The provided output file already exists. To force overwriting the config file, set the --force or -F flag.",
             exits=1,
         )
-    lang = util.find_matching_language(lang)
     config = init_config(
         lang=lang,
         pipeline=pipeline,

spacy/errors.py

@@ -215,7 +215,7 @@ class Warnings(metaclass=ErrorsWithCodes):
     W123 = ("Argument {arg} with value {arg_value} is used instead of {config_value} as specified in the config. Be "
             "aware that this might affect other components in your pipeline.")
 # New warnings added in v4.x
-    W124 = ("Language code {lang} has been renamed to {renamed_lang} in spaCy v4")
+    W124 = ("Language code '{lang}' was not found and replaced with '{renamed_lang}'. Language codes like 'xx' and 'is' were renamed to 'mul' and 'isl' in v4.")
 
 
 class Errors(metaclass=ErrorsWithCodes):

spacy/util.py

@@ -302,6 +302,8 @@ def find_matching_language(lang: str) -> Optional[str]:
     # is labeled that way is probably trying to be distinct from 'zh' and
     # shouldn't automatically match.
     match = langcodes.closest_supported_match(lang, possible_languages, max_distance=9)
+    if match is not None:
+        warnings.warn(Warnings.W124.format(lang=lang, renamed_lang=match))
     return match