Morphic Debugging Tricks

My Morph is displaying a "red square of death"! What do I do?

All Pharo Versions (thanks Sebastian)

1. Invoke #drawOn: manually

m drawOn: (NullCanvas new).

2. After the bug is fixed, resume drawing for a Morph instance

m resumeAfterDrawError.

Pharo 2.0 and later

Click on it to open a debugger (Steph).

Pharo 1.4

There is still hope… (thanks to Ben)

Find the method fullDrawOn: and replace

on: Error do: [:err |

self setProperty: #errorOnDraw toValue: true.

self setProperty: #drawError toValue: err freeze.

^ self drawErrorOn: aCanvas ]

with:

value

Now you will have a debugger instead of the red square of death. But do it at you own risk.

Wiki