diff --git a/klamath/basic.py b/klamath/basic.py
index 86c9d59..c1d1d15 100644
--- a/klamath/basic.py
+++ b/klamath/basic.py
@@ -77,7 +77,7 @@ def parse_datetime(data: bytes) -> list[datetime]:
         year, *date_parts = parse_int2(data[ii:ii + 12])
         try:
             dt = datetime(year + 1900, *date_parts)
-        except ValueError as err:
+        except ValueError:
             dt = datetime(1900, 1, 1, 0, 0, 0)
             logger.info(f'Invalid date {[year] + date_parts}, setting {dt} instead')
         dts.append(dt)
diff --git a/pyproject.toml b/pyproject.toml
index afb1d81..5ca097d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,3 @@
-[build-system]
-requires = ["hatchling"]
-build-backend = "hatchling.build"
-
 [project]
 name = "klamath"
 description = "GDSII format reader/writer"
@@ -84,7 +80,6 @@ lint.ignore = [
     "ANN002",   # *args
     "ANN003",   # **kwargs
     "ANN401",   # Any
-    "ANN101",   # self: Self
     "SIM108",   # single-line if / else assignment
     "RET504",   # x=y+z; return x
     "PIE790",   # unnecessary pass