diff --git a/masque/builder/pather.py b/masque/builder/pather.py
index 11e4d80..0f4fad9 100644
--- a/masque/builder/pather.py
+++ b/masque/builder/pather.py
@@ -430,7 +430,6 @@ class Pather(Builder):
             **kwargs,
             )
 
-
     def path_into(
             self,
             portspec_src: str,
@@ -465,7 +464,7 @@ class Pather(Builder):
 
         angle = (port_dst.rotation - port_src.rotation) % (2 * pi)
 
-        src_ne = port_src.rotation % (2 * pi) > (3 * pi /4)     # path from src will go north or east
+        src_ne = port_src.rotation % (2 * pi) > (3 * pi / 4)     # path from src will go north or east
 
         def get_jog(ccw: SupportsBool, length: float) -> float:
             tool = self.tools.get(portspec_src, self.tools[None])
@@ -511,7 +510,7 @@ class Pather(Builder):
                 self.path_to(portspec_src, not ccw2, y=yd - jog, **src_args)
                 self.path_to(portspec_src, ccw2, x=xd, **dst_args)
         elif numpy.isclose(angle, 0):
-            raise BuildError(f'Don\'t know how to route a U-bend at this time!')
+            raise BuildError('Don\'t know how to route a U-bend at this time!')
         else:
             raise BuildError(f'Don\'t know how to route ports with relative angle {angle}')
 
diff --git a/masque/file/utils.py b/masque/file/utils.py
index 87c3d67..898bd05 100644
--- a/masque/file/utils.py
+++ b/masque/file/utils.py
@@ -57,7 +57,7 @@ def preflight(
         refs = lib.referenced_patterns()
         dangling = refs - set(lib.keys())
         if dangling:
-            msg = 'Dangling refs in found: ' + pformat(dangling)
+            msg = 'Dangling refs found: ' + pformat(dangling)
             if allow_dangling_refs is None:
                 logger.warning(msg)
             else:
@@ -75,8 +75,11 @@ def preflight(
 
     if prune_empty_patterns:
         pruned = lib.prune_empty()
-        logger.info(f'Preflight pruned {len(pruned)} empty patterns')
-        logger.debug('Pruned: ' + pformat(pruned))
+        if pruned:
+            logger.info(f'Preflight pruned {len(pruned)} empty patterns')
+            logger.debug('Pruned: ' + pformat(pruned))
+        else:
+            logger.debug('Preflight found no empty patterns')
 
     if wrap_repeated_shapes:
         lib.wrap_repeated_shapes()