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The Agency debugger ​

Still a work in progress

Agency has a very good built-in debugger. Lets try using it. Put the following code in a file called test.agency:

ts
node main() {
 const name = "world"
 const greeting = llm("Say hello to ${name}!")
 print(greeting)
}

and then invoke the debugger using

agency debug test.agency

Here are some things you may want to do with the debugger:

  • Step forward: Press s or the down arrow.
  • Continue until you hit a debugger statement: Press c or space.
  • Rewind or step backwards: Press the up arrow, or press r to see a list of checkpoints. Press up/down to scroll and you'll see the line each checkpoint is for.
  • Override the value of a variable: Enter :set varName=newValue. Then when you press s, the next statement will execute with the variable's value overwritten.
  • Cycle between all the different panels: tab and shift+tab. Once a panel has focus, you can press the up or down arrow keys to scroll, or press z to zoom, temporarily making that panel full screen.
  • In the threads panel, you can press [ or ] to cycle between the different threads.

Options ​

  • --node <name> — node to execute (defaults to main).
  • --rewind-size <n> — size of the rolling checkpoint window. Defaults to 30. Larger values let you rewind further at the cost of memory.
  • --trace <file> — load and inspect an existing .trace file instead of running the program live.
  • --checkpoint <file> — load a saved checkpoint file and start the debugger from that point.
  • --dist-dir <dir> — import pre-compiled JS from this directory instead of compiling the .agency file on the fly. Useful when you've already built your project and want to skip the compile step.