Print traceback for internal command errors (#198)

Closes #196

Author: stefanv

spin/__main__.py

@@ -3,6 +3,8 @@
 import importlib.util
 import os
 import sys
+import textwrap
+import traceback
 
 import click
 
@@ -152,8 +154,25 @@ def group(ctx):
 
     try:
         group()
-    except Exception as e:
-        print(f"Error: {e}; aborting.", file=sys.stderr)
+    except Exception:
+        click.secho("\n" + traceback.format_exc(limit=-3), fg="red", file=sys.stderr)
+        click.secho(
+            textwrap.dedent(
+                f"""\
+        An internal error has occurred. Please file a bug report at
+
+          https://github.com/scientific-python/spin
+
+        including the above traceback and the following information:
+
+          spin: {__version__}, package: {proj_name}
+
+        Aborting."""
+            ),
+            fg="red",
+            bold=True,
+            file=sys.stderr,
+        )
         sys.exit(1)