diff --git a/babel/messages/catalog.py b/babel/messages/catalog.py
index 5686b3141..d0bf6f910 100644
--- a/babel/messages/catalog.py
+++ b/babel/messages/catalog.py
@@ -74,7 +74,7 @@ def get_close_matches(word, possibilities, n=3, cutoff=0.6):
     \%
         (?:\(([\w]*)\))?
         (
-            [-#0\ +]?(?:\*|[\d]+)?
+            [-#0+]?(?:\*|[\d]+)?
             (?:\.(?:\*|[\d]+))?
             [hlL]?
         )
diff --git a/babel/messages/frontend.py b/babel/messages/frontend.py
index c80bcbeb8..a046f81e4 100644
--- a/babel/messages/frontend.py
+++ b/babel/messages/frontend.py
@@ -198,13 +198,13 @@ def finalize_options(self):
             raise OptionError('you must specify either the output file or the base directory')
 
     def run(self):
-        n_errors = 0
+        n_warnings = 0
         for domain in self.domain:
             for errors in self._run_domain(domain).values():
-                n_errors += len(errors)
-        if n_errors:
-            self.log.error('%d errors encountered.', n_errors)
-        return 1 if n_errors else 0
+                n_warnings += len(errors)
+        if n_warnings:
+            self.log.warning('%d warnings encountered.', n_warnings)
+        return 0
 
     def _get_po_mo_triples(self, domain: str):
         if not self.input_file:
@@ -262,7 +262,7 @@ def _run_domain(self, domain):
             catalogs_and_errors[catalog] = catalog_errors = list(catalog.check())
             for message, errors in catalog_errors:
                 for error in errors:
-                    self.log.error('error: %s:%d: %s', po_file, message.lineno, error)
+                    self.log.warning('warning: %s:%d: %s', po_file, message.lineno, error)
 
             self.log.info('compiling catalog %s to %s', po_file, mo_file)