Debug Printer

The whole Searge SDXL workflow runs on a hidden bus - the SRG_DATA_STREAM - that carries every setting from the input boxes to the Magic Box. That's convenient right up until something's wrong and you can't see what's in the stream. The Debug Printer is the node that opens the hood: drop it anywhere in the data-stream chain and it prints the stream's contents to the ComfyUI console when the workflow runs.

It's a diagnostic tool, plain and simple. You won't leave it in a production workflow, but when your images look wrong and you're not sure whether the model selector, the parameters box, or the prompt encoder is misbehaving, this is how you check what the pipeline actually received versus what you thought you set.

How it works

The node sits inline on the data stream - stream in, same stream out, unchanged - and as a side effect it prints what's passing through. It's an output node, so it fires on every run even if nothing downstream depends on it. Put it right after the box you suspect and read the console to see the values that box wrote into the stream.

The inputs and outputs that matter

• enabled (boolean, default true) - the on/off switch. Set it false to silence the printer without deleting it from your graph, which is handy for leaving it wired but dormant.
• data (optional SRG_DATA_STREAM) - the stream to inspect and pass through.
• prefix (optional string) - a label prepended to the output. If you've got several printers in one graph, give each a distinct prefix so you can tell their console lines apart.

The single output is data (SRG_DATA_STREAM) - the same stream, untouched, so you can splice this node in without breaking the chain.

How to install it

Manager: search SeargeSDXL, install, restart. Manual, opencv dependency first:

python -m pip install opencv-python
cd ComfyUI/custom_nodes
git clone https://github.com/SeargeDP/SeargeSDXL.git

Restart ComfyUI. No model files needed.

Common issues & troubleshooting

Nothing prints. Two things to check. First, enabled has to be true. Second - and this is a real historical gotcha - the Debug Printer was actually broken in the v4.0 release; SeargeDP noted it wasn't connected in any of the v4.0 workflows so the bug went unnoticed, and it was fixed in v4.1. So if you're on an ancient version, update the pack. git pull in the pack directory and restart.

Where's the output? It goes to the ComfyUI server console - the terminal window running ComfyUI - not the browser UI. If you launched ComfyUI by double-clicking and have no visible console, you won't see it; run from a terminal so you can read stdout.

Can't tell which printer is which. Use the prefix field. With several printers in a graph, an unlabeled dump of raw stream contents is hard to attribute; a short prefix per printer makes the console readable.