The debugger
The debugger is a tool window for inspecting a running project: logging messages, pausing and stepping the runtime, watching threads, and keeping an eye on performance and memory. It is aimed at anyone tracking down why a project misbehaves.
Opening the debugger
Open the Tools menu and choose Debugger. It also opens automatically when a breakpoint block runs, pausing the project at that point.
The debugger adds two blocks to the Control-style tools it registers: log, warn, and error blocks that send a message to the log at that severity, and a breakpoint block that pauses the project.
Pausing and stepping
When the project is paused (by a breakpoint, or the pause button), the debugger toolbar shows a Paused indicator with Resume and Step buttons. Step advances the project by exactly one frame so you can watch state change frame by frame.
You can also pause from the stage: the settings Show Pause Button option adds a pause/play button next to the green flag (also Alt+X, Option+X on macOS), and Show Frame Step Button adds a single-frame step button while paused.
The tabs
Logs shows every message, newest activity in view:
- Each entry has a timestamp, a severity icon (log, warn, or error), the message, and a link to the block and sprite that produced it. Clicking the link jumps to that block: it switches to the sprite, opens the Code tab, and scrolls the block into view.
- Filter the log with a search box, the log / warn / error severity toggles, and a per-sprite dropdown.
- Export downloads the log as a text file, and Clear empties it.
- Optional automatic logs (green flag clicks, broadcasts, clone creation, and hitting the clone limit) can be turned on in the debugger settings.
Threads shows the scripts currently running as a live tree, with each thread's call stack of blocks and the currently executing block highlighted. Compiled threads cannot be stepped and show no stack detail.
Performance charts the frame rate (against your target FPS) and the live clone count while the project runs.
Memory shows counts of clones, variables, variable characters, lists, and list items, turning to a warning colour when they climb high, plus charts of variable data size and list items and a list of variable values.
Settings
The debugger's options live on the Debugger page of the settings window: highlight running blocks, clear logs on green flag, log green flag clicks, log clone creation, log the clone-limit warning, log broadcasts, and animate the graphs.