- Changes a lot of error messages for clarity
- Clearer `__repr__` for `Placeholder`, `File`, and `MetaProduct`
- Default placeholders can be used in `pipeline.yaml` without defining `env.yaml`
- Better formatting for displaying DAG build and render errors
- Spec API initializes task spec as `SQLDump` if product has suffix `.csv` or `.parquet`
- Coloring CLI error traceback
- Spec API skips `SourceLoader` if passing an absolute path
- `DAG.clients` validates keys (using `DAGClients`)
- `params` available as hook argument
- Rewritten Spec API documentation