diff --git a/capa/features/common.py b/capa/features/common.py
index 67c9ed0d..a939f16e 100644
--- a/capa/features/common.py
+++ b/capa/features/common.py
@@ -11,7 +11,7 @@ import abc
 import codecs
 import logging
 import collections
-from typing import TYPE_CHECKING, Set, Dict, List, Union, Optional, Sequence
+from typing import TYPE_CHECKING, Set, Dict, List, Union, Optional
 
 if TYPE_CHECKING:
     # circular import, otherwise
@@ -279,12 +279,12 @@ class Regex(String):
             flags |= re.IGNORECASE
         try:
             self.re = re.compile(pat, flags)
-        except re.error:
+        except re.error as exc:
             if value.endswith("/i"):
                 value = value[: -len("i")]
             raise ValueError(
                 "invalid regular expression: %s it should use Python syntax, try it at https://pythex.org" % value
-            )
+            ) from exc
 
     def evaluate(self, ctx, short_circuit=True):
         capa.perf.counters["evaluate.feature"] += 1
diff --git a/capa/features/insn.py b/capa/features/insn.py
index 50dd6133..7d01b7c6 100644
--- a/capa/features/insn.py
+++ b/capa/features/insn.py
@@ -72,6 +72,7 @@ class Offset(Feature):
         super(Offset, self).__init__(value, description=description)
 
     def get_value_str(self):
+        assert isinstance(self.value, int)
         return hex(self.value)
 
 
diff --git a/capa/main.py b/capa/main.py
index 373172b2..e9a2b728 100644
--- a/capa/main.py
+++ b/capa/main.py
@@ -461,6 +461,7 @@ def get_workspace(path, format_, sigpaths):
 
     # lazy import enables us to not require viv if user wants SMDA, for example.
     import viv_utils
+    import viv_utils.flirt
 
     logger.debug("generating vivisect workspace for: %s", path)
     # TODO should not be auto at this point, anymore
@@ -1143,9 +1144,7 @@ def main(argv=None):
 
 
 def ida_main():
-    import capa.rules
     import capa.ida.helpers
-    import capa.render.default
     import capa.features.extractors.ida.extractor
 
     logging.basicConfig(level=logging.INFO)
@@ -1166,7 +1165,7 @@ def ida_main():
 
     rules_path = os.path.join(get_default_root(), "rules")
     logger.debug("rule path: %s", rules_path)
-    rules = get_rules(rules_path)
+    rules = get_rules([rules_path])
     rules = capa.rules.RuleSet(rules)
 
     meta = capa.ida.helpers.collect_metadata([rules_path])
diff --git a/capa/optimizer.py b/capa/optimizer.py
index 0408bf07..997abd6c 100644
--- a/capa/optimizer.py
+++ b/capa/optimizer.py
@@ -47,7 +47,7 @@ def optimize_statement(statement):
 
     if isinstance(statement, (ceng.And, ceng.Or, ceng.Some)):
         # has .children
-        statement.children = sorted(statement.children, key=lambda n: get_node_cost(n))
+        statement.children = sorted(statement.children, key=get_node_cost)
         return
     elif isinstance(statement, (ceng.Not, ceng.Range)):
         # has .child
diff --git a/scripts/show-features.py b/scripts/show-features.py
index f07dcf75..00c1eb05 100644
--- a/scripts/show-features.py
+++ b/scripts/show-features.py
@@ -79,6 +79,7 @@ import capa.exceptions
 import capa.render.verbose as v
 import capa.features.common
 import capa.features.freeze
+import capa.features.address
 import capa.features.extractors.base_extractor
 from capa.helpers import log_unsupported_runtime_error
 
@@ -108,7 +109,7 @@ def main(argv=None):
 
     try:
         sig_paths = capa.main.get_signatures(args.signatures)
-    except (IOError) as e:
+    except IOError as e:
         logger.error("%s", str(e))
         return -1
 
diff --git a/setup.cfg b/setup.cfg
index 5e0292f4..87eef850 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,3 +19,10 @@ test = pytest
 ignore = E203, E302, E402, E501, E712, E722, E731, W291, W503
 max-line-length = 180
 statistics = True
+
+
+[pylint.FORMAT]
+max-line-length = 180
+
+[pylint]
+disable = missing-docstring,invalid-name,import-outside-toplevel,redefined-outer-name,consider-using-f-string
\ No newline at end of file