Better error message for people running icat on systems with outdated/broken ImageMagick

kittens/icat/main.py

@@ -28,7 +28,8 @@ from kitty.utils import (
 
 from ..tui.images import (
     ConvertFailed, Dispose, GraphicsCommand, NoImageMagick, OpenFailed,
-    RenderedImage, fsenc, identify, render_as_single_image, render_image
+    OutdatedImageMagick, RenderedImage, fsenc, identify,
+    render_as_single_image, render_image
 )
 from ..tui.operations import clear_images_on_screen, raw_mode
 
@@ -559,6 +560,9 @@ def main(args: List[str] = sys.argv) -> None:
             process_single_item(item, cli_opts, parsed_opts, url_pat)
         except NoImageMagick as e:
             raise SystemExit(str(e))
+        except OutdatedImageMagick as e:
+            print(e.detailed_error, file=sys.stderr)
+            raise SystemExit(str(e))
         except ConvertFailed as e:
             raise SystemExit(str(e))
         except OpenFailed as e:

kittens/tui/images.py

@@ -118,6 +118,13 @@ class NoImageMagick(Exception):
     pass
 
 
+class OutdatedImageMagick(ValueError):
+
+    def __init__(self, detailed_error: str):
+        super().__init__('ImageMagick on this system is too old ImageMagick 7+ required which was first released in 2016')
+        self.detailed_error = detailed_error
+
+
 last_imagemagick_cmd: Sequence[str] = ()
 
 
@@ -237,7 +244,7 @@ def render_image(
                 f.canvas_width, f.canvas_height = map(positive_int, sz.split('x', 1))
                 f.canvas_x, f.canvas_y = map(int, pos.split('+', 1))
             except Exception:
-                raise ValueError(f'Unexpected output filename: {x!r} produced by ImageMagick command: {last_imagemagick_cmd}')
+                raise OutdatedImageMagick(f'Unexpected output filename: {x!r} produced by ImageMagick command: {last_imagemagick_cmd}')
             f.path = output_prefix + f'-{index}.{m.mode}'
             os.rename(os.path.join(tdir, x), f.path)
             check_resize(f)