The bug was fixed. Please use Dandelion 0.4final2. Thanks Mr. Yutaka Kamite for reporting that. This version supports Rose Petal file output. Actually, a pretty good Rose Petal outputter is emerging.
Current snapshot is here .
It runs on Squeak2.8 and supports SMIX output. SMIX outputter early access - see SMIX page. Although it is not complete version, you will know where the Dandelion is directed to. This is based on Dandelion 0.4 pre-alpha version. I confirmed that Dandelion 0.3 will run on Mac Squeak 2.7.