What causes stack overflow errors in GDScript?

A function recursed without a base case — mutual recursion between callbacks, a property setter that assigns itself, or a signal handler that re-emits its own signal.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix “Stack overflow (stack size: 1024)” Recursion Errors in Godot

Quick answer: Find the cycle in the stack trace, add the missing base case, and in setters write to the backing field instead of the property to avoid self-triggering.

GDScript caps the call stack and stops the runaway with this error. The stack trace shows the repeating cycle — the fix is breaking it. Here are the classic cycles.

How to fix it

1. Fix self-assigning setters

In set(value): blocks, assigning the property itself (health = value) re-enters the setter forever — assign the backing variable or use the Godot 4 field-style pattern with a distinct variable name.

2. Break signal echo loops

A handler that changes a value which emits the same signal loops; guard with an _updating flag or compare old vs new before re-emitting.

3. Give recursion a base case

Tree walks and flood fills need an explicit stop (depth limit, visited set) — and for big maps convert to an iterative loop with your own stack.

4. Read the repeating frame pair

The error's stack trace shows the two or three functions cycling; that pair is the bug, whatever the entry point was.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Godot error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.