diff --git a/masque/builder/builder.py b/masque/builder/builder.py
index 243891d..68de9e6 100644
--- a/masque/builder/builder.py
+++ b/masque/builder/builder.py
@@ -1,17 +1,15 @@
 """
 Simplified Pattern assembly (`Builder`)
 """
-from typing import Self, Sequence, Mapping, Literal, overload
+from typing import Self, Sequence, Mapping
 import copy
 import logging
 
-from numpy import pi
 from numpy.typing import ArrayLike
 
 from ..pattern import Pattern
-from ..ref import Ref
 from ..library import ILibrary
-from ..error import PortError, BuildError
+from ..error import BuildError
 from ..ports import PortList, Port
 from ..abstract import Abstract
 
diff --git a/masque/builder/pather.py b/masque/builder/pather.py
index b115f65..b1c8d47 100644
--- a/masque/builder/pather.py
+++ b/masque/builder/pather.py
@@ -399,12 +399,12 @@ class Pather(Builder):
         is_horizontal = numpy.isclose(port.rotation % pi, 0)
         if is_horizontal:
             if y is not None:
-                raise BuildError(f'Asked to path to y-coordinate, but port is horizontal')
+                raise BuildError('Asked to path to y-coordinate, but port is horizontal')
             if position is None:
                 position = x
         else:
             if x is not None:
-                raise BuildError(f'Asked to path to x-coordinate, but port is vertical')
+                raise BuildError('Asked to path to x-coordinate, but port is vertical')
             if position is None:
                 position = y
 
diff --git a/masque/builder/renderpather.py b/masque/builder/renderpather.py
index 9b8ba96..e35a672 100644
--- a/masque/builder/renderpather.py
+++ b/masque/builder/renderpather.py
@@ -12,15 +12,13 @@ from numpy import pi
 from numpy.typing import ArrayLike
 
 from ..pattern import Pattern
-from ..ref import Ref
-from ..library import ILibrary, Library
+from ..library import ILibrary
 from ..error import PortError, BuildError
 from ..ports import PortList, Port
 from ..abstract import Abstract
 from ..utils import SupportsBool
 from .tools import Tool, RenderStep
 from .utils import ell
-from .builder import Builder
 
 
 logger = logging.getLogger(__name__)
@@ -491,12 +489,12 @@ class RenderPather(PortList):
         is_horizontal = numpy.isclose(port.rotation % pi, 0)
         if is_horizontal:
             if y is not None:
-                raise BuildError(f'Asked to path to y-coordinate, but port is horizontal')
+                raise BuildError('Asked to path to y-coordinate, but port is horizontal')
             if position is None:
                 position = x
         else:
             if x is not None:
-                raise BuildError(f'Asked to path to x-coordinate, but port is vertical')
+                raise BuildError('Asked to path to x-coordinate, but port is vertical')
             if position is None:
                 position = y
 
diff --git a/masque/builder/tools.py b/masque/builder/tools.py
index 1185185..bc49c56 100644
--- a/masque/builder/tools.py
+++ b/masque/builder/tools.py
@@ -262,7 +262,6 @@ class BasicTool(Tool, metaclass=ABCMeta):
     default_out_ptype: str
     """ Default value for out_ptype """
 
-
     @dataclass(frozen=True, slots=True)
     class LData:
         """ Data for planL """
diff --git a/masque/builder/utils.py b/masque/builder/utils.py
index b3d200d..f23e8d2 100644
--- a/masque/builder/utils.py
+++ b/masque/builder/utils.py
@@ -122,6 +122,8 @@ def ell(
     orig_offsets = numpy.array([p.offset for p in ports.values()])
     rot_offsets = (rot_matrix @ orig_offsets.T).T
 
+#    ordering_base = rot_offsets.T * [[1], [-1 if ccw else 1]]      # could work, but this is actually a more complex routing problem
+#    y_order = numpy.lexsort(ordering_base)                         #  (need to make sure we don't collide with the next input port @ same y)
     y_order = ((-1 if ccw else 1) * rot_offsets[:, 1]).argsort(kind='stable')
     y_ind = numpy.empty_like(y_order, dtype=int)
     y_ind[y_order] = numpy.arange(y_ind.shape[0])
diff --git a/masque/shapes/arc.py b/masque/shapes/arc.py
index e6ce411..1841aed 100644
--- a/masque/shapes/arc.py
+++ b/masque/shapes/arc.py
@@ -1,6 +1,5 @@
 from typing import Any
 import copy
-import math
 
 import numpy
 from numpy import pi
@@ -231,7 +230,7 @@ class Arc(Shape):
 
         def get_thetas(inner: bool) -> NDArray[numpy.float64]:
             """ Figure out the parameter values at which we should place vertices to meet the arclength constraint"""
-            dr = -self.width / 2.0 * (-1 if inner else 1)
+            #dr = -self.width / 2.0 * (-1 if inner else 1)
 
             n_pts = numpy.ceil(2 * pi * max(self.radii) / max_arclen).astype(int)
             arc_lengths, thetas = get_arclens(n_pts, *a_ranges[0 if inner else 1])