C overflow

src/gitfetch/cache.py

@@ -255,7 +255,27 @@ def _is_cache_expired(self, cached_at: datetime) -> bool:
         Returns:
             True if expired, False otherwise
         """
-        expiry_time = datetime.now() - timedelta(minutes=self.cache_expiry_minutes)
+        # Defensive handling: ensure cache_expiry_minutes is a reasonable int
+        # and avoid passing an extremely large integer to timedelta which can
+        # raise OverflowError on some platforms (assuming on 32-bit builds).
+        try:
+            minutes = int(self.cache_expiry_minutes)
+        except Exception:
+            minutes = 15
+
+        # Enforce sensible bounds: minimum 1 minute, cap to MAX_MINUTES
+        # (10 years expressed in minutes). This prevents OverflowError while
+        # still allowing very long cache durations when intentionally set.
+        MAX_MINUTES = 5256000  # 10 years
+        minutes = max(1, min(minutes, MAX_MINUTES))
+
+        try:
+            expiry_time = datetime.now() - timedelta(minutes=minutes)
+        except OverflowError:
+            # In the unlikely event timedelta still overflows, treat cache as
+            # non-expired (safe default) to avoid crashing the program.
+            return False
+
         return cached_at < expiry_time
 
     def list_cached_accounts(self) -> list[tuple[str, datetime]]:

src/gitfetch/cli.py

@@ -441,7 +441,19 @@ def main() -> int:
             return 0
 
         except Exception as e:
-            print(f"Error: {e}", file=sys.stderr)
+            # When debugging, print full traceback to help diagnose issues
+            # (useful when users report errors from package builds / other
+            # environments where the short error message is not enough).
+            try:
+                import os
+                import traceback
+                if os.environ.get('GITFETCH_DEBUG'):
+                    traceback.print_exc()
+                else:
+                    print(f"Error: {e}", file=sys.stderr)
+            except Exception:
+                # Fallback to simple message if traceback printing fails
+                print(f"Error: {e}", file=sys.stderr)
             return 1
 
     except KeyboardInterrupt:

src/gitfetch/display.py

@@ -951,10 +951,18 @@ def _build_month_line(self, weeks_data: list) -> str:
 
             try:
                 date_obj = datetime.fromisoformat(first_day)
-            except ValueError:
+                # Validate year is in reasonable range to avoid C int overflow
+                if date_obj.year < 1900 or date_obj.year > 9999:
+                    continue
+            except (ValueError, OverflowError):
                 continue
 
-            month_abbr = date_obj.strftime('%b')
+            try:
+                month_abbr = date_obj.strftime('%b')
+            except (ValueError, OverflowError):
+                # strftime can fail with years outside 1900-9999
+                continue
+
             if month_abbr != last_month:
                 month_chars.append(month_abbr)
                 last_month = month_abbr
@@ -986,8 +994,11 @@ def _build_month_line_spaced(self, weeks_data: list) -> str:
 
             try:
                 date_obj = datetime.fromisoformat(first_day)
+                # Validate year is in reasonable range to avoid C int overflow
+                if date_obj.year < 1900 or date_obj.year > 9999:
+                    continue
                 current_month = date_obj.month
-            except ValueError:
+            except (ValueError, OverflowError):
                 continue
 
             # Check if this is a new month
@@ -1003,6 +1014,9 @@ def _build_month_line_spaced(self, weeks_data: list) -> str:
                             prev_date_obj = datetime.fromisoformat(
                                 prev_first_day
                             )
+                            # Validate year is in reasonable range
+                            if prev_date_obj.year < 1900 or prev_date_obj.year > 9999:
+                                continue
                             prev_month = prev_date_obj.month
                             if current_month != prev_month:
                                 # New month - add spacing and month name
@@ -1016,7 +1030,7 @@ def _build_month_line_spaced(self, weeks_data: list) -> str:
                                 needed_space = max(1, calc)
                                 month_line += " " * needed_space
                                 month_line += month_name
-                        except ValueError:
+                        except (ValueError, OverflowError):
                             pass
 
         return f"    {month_line}"
@@ -1298,8 +1312,11 @@ def _format_date(self, date_string: str) -> str:
         """
         try:
             dt = datetime.fromisoformat(date_string.replace('Z', '+00:00'))
+            # Validate year is in reasonable range to avoid C int overflow
+            if dt.year < 1900 or dt.year > 9999:
+                return date_string
             return dt.strftime('%B %d, %Y')
-        except (ValueError, AttributeError):
+        except (ValueError, AttributeError, OverflowError):
             return date_string
 
     def _get_contribution_block(self, count: int) -> str: