SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

checkpoint-system

claude-code claude-opus-4-8 ✗ failed GOOD_FAILURE ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_FAILUREHonest miss, the agent ran correctly but couldn't solve it. Expected for a hard task; the task is sound.
SubtypeImplementation Bugs
EvidenceTest output: "VALIDATION_FAILED: beacon export must be wired to the Beacon Sprite2D in the scene". Agent created checkpoint.tscn with `beacon = NodePath("Beacon")` syntax, but the validator checks `beacon_ref is Sprite2D` and `beacon_ref != beacon_node`, indicating that the NodePath syntax didn't properly wire the node reference. The agent correctly implemented the GDScript logic in checkpoint.gd (signals, exports, apply_charge, _on_body_entered, reset) and created all required nodes (CollisionShape2D, Beacon Sprite2D, ChargeLabel Label) with correct signal wiring, but failed to correctly assign the node references in the .tscn file format.
Root causeThe agent misunderstood the correct Godot .tscn syntax for wiring exported node references. They used `beacon = NodePath("Beacon")` in the scene file, which doesn't properly resolve to a node reference at runtime. The GDScript implementation was correct, but the scene file property binding syntax was incorrect.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
15 tool calls · 3 tool types · 15 steps
Build an animated checkpoint beacon for a 2D platformer. Create `scenes/checkpoint.tscn` with an `Area2D` root node named `Checkpoint` (attach `scripts/checkpoint.gd`). Give it these children: - a `CollisionShape2D` using a `RectangleShape2D` sized 32×32, - a `Sprite2D` named `Beacon` (the visual that pulses as the checkpoint charges), - a `Label` named `ChargeLabel`. Wire the area so bodies entering it reach the script's `_on_body_entered(body)` handler. In `scripts/checkpoint.gd`, implement the `Checkpoint` class: - Export an int `checkpoint_id` (default `0`) and a bool `is_final_checkpoint` (default `false`). Expose a public bool `is_active` (default `false`). - Export a `Gradient` resource named `charge_gradient`, authored in the scene with three color stops: offset `0.0` is deep blue `Color(0.1, 0.2, 0.6)`, offset `0.5` is bright cyan `Color(0.2, 0.9, 1.0)`, offset `1.0` is white `Color(1.0, 1.0, 1.0)`. - Export a `Curve` resource named `scale_curve`, authored so that sampling its baked value returns `1.0` at position `0.0`, `1.8` at position `0.5`, and `2.0` at position `1.0`. - Export a `Sprite2D` reference named `beacon` and a `Label` reference named `charge_label`, each wired in the scene to the `Beacon` and `ChargeLabel` nodes. Behavior: - `apply_charge(t: float)` drives the beacon's look for a charge fraction `t` in `[0, 1]`: set `beacon.modulate` to `charge_gradient` sampled at `t`, and set `beacon.scale` to `Vector2.ONE * scale_curve.sample_baked(t)`. - Only the player can light a checkpoint , the player belongs to the `"Player"` group; any other body that enters must be ignored. The first time the player reaches an unlit checkpoint, set it active, drive the beacon to full charge by calling `apply_charge(1.0)`, write the checkpoint's id into `charge_label.text`, and emit `activated` carrying `checkpoint_id`. While it stays lit, re-touching it does nothing. - A final checkpoint (`is_final_checkpoint == true`) must also emit `level_complete` at the moment it activates. - `reset()` re-arms the checkpoint (sets `is_active` back to false) so it can be lit again. Declare the signals `activated(id: int)` and `level_complete`.
I'll create the script and scene files directly.
Write
{
  "file_path": "/home/user/task/scripts/checkpoint.gd",
  "content": "class_name Checkpoint\nextends Area2D\n\n## Emitted when the player first lights this checkpoint.\nsignal activated(id: int)\n## Emitted alongside `activated` when a final checkpoint lights.\nsignal level_complete\n\n@export var checkpoint_id: int = 0\n@export var is_final_checkpoint: bool = false\nvar is_active: bool = false\n\n@export var charge_gradient: Gradient\n@export var scale_curve: Curve\n\n@export var beacon: Sprite2D\n@export var charge_label: Label\n\n\n## Drives the beacon's look for a charge fraction `t` in [0, 1].\nfunc apply_charge(t: float) -> void:\n\tbeacon.modulate = charge_gradient.sample(t)\n\tbeacon.scale = Vector2.ONE * scale_curve.sample_baked(t)\n\n\nfunc _on_body_entered(body: Node) -> void:\n\t# Only the player can light a checkpoint; ignore everything else.\n\tif not body.is_in_group(\"Player\"):\n\t\treturn\n\t# Once lit, re-touching does nothing until reset().\n\tif is_active:\n\t\treturn\n\tis_active = true\n\tapply_charge(1.0)\n\tcharge_label.text = str(checkpoint_id)\n\tactivated.emit(checkpoint_id)\n\tif is_final_checkpoint:\n\t\tlevel_complete.emit()\n\n\n## Re-arms the checkpoint so it can be lit again.\nfunc reset() -> void:\n\tis_active = false\n"
}
output
<tool_use_error>File has not been read yet. Read it first before writing to it.</tool_use_error>

[error] tool reported failure
Read
{
  "file_path": "/home/user/task/scripts/checkpoint.gd"
}
output
1	extends Area2D
2	class_name Checkpoint
3	
4	func _ready() -> void:
5		pass
6
Write
{
  "file_path": "/home/user/task/scripts/checkpoint.gd",
  "content": "class_name Checkpoint\nextends Area2D\n\n## Emitted when the player first lights this checkpoint.\nsignal activated(id: int)\n## Emitted alongside `activated` when a final checkpoint lights.\nsignal level_complete\n\n@export var checkpoint_id: int = 0\n@export var is_final_checkpoint: bool = false\nvar is_active: bool = false\n\n@export var charge_gradient: Gradient\n@export var scale_curve: Curve\n\n@export var beacon: Sprite2D\n@export var charge_label: Label\n\n\n## Drives the beacon's look for a charge fraction `t` in [0, 1].\nfunc apply_charge(t: float) -> void:\n\tbeacon.modulate = charge_gradient.sample(t)\n\tbeacon.scale = Vector2.ONE * scale_curve.sample_baked(t)\n\n\nfunc _on_body_entered(body: Node) -> void:\n\t# Only the player can light a checkpoint; ignore everything else.\n\tif not body.is_in_group(\"Player\"):\n\t\treturn\n\t# Once lit, re-touching does nothing until reset().\n\tif is_active:\n\t\treturn\n\tis_active = true\n\tapply_charge(1.0)\n\tcharge_label.text = str(checkpoint_id)\n\tactivated.emit(checkpoint_id)\n\tif is_final_checkpoint:\n\t\tlevel_complete.emit()\n\n\n## Re-arms the checkpoint so it can be lit again.\nfunc reset() -> void:\n\tis_active = false\n"
}
output
The file /home/user/task/scripts/checkpoint.gd has been updated successfully. (file state is current in your context , no need to Read it back)
Bash
ls -la /home/user/task/scenes/checkpoint.tscn 2>&1; echo "---"; cat /home/user/task/scenes/checkpoint.tscn 2>&1
output
-rw-r--r-- 1 user user 73 Jun 21 07:51 /home/user/task/scenes/checkpoint.tscn
---
[gd_scene load_steps=1 format=3]

[node name="Checkpoint" type="Area2D"]

[stdout]
-rw-r--r-- 1 user user 73 Jun 21 07:51 /home/user/task/scenes/checkpoint.tscn
---
[gd_scene load_steps=1 format=3]

[node name="Checkpoint" type="Area2D"]
Read
{
  "file_path": "/home/user/task/scenes/checkpoint.tscn"
}
output
1	[gd_scene load_steps=1 format=3]
2	
3	[node name="Checkpoint" type="Area2D"]
4
Write
{
  "file_path": "/home/user/task/scenes/checkpoint.tscn",
  "content": "[gd_scene load_steps=5 format=3]\n\n[ext_resource type=\"Script\" path=\"res://scripts/checkpoint.gd\" id=\"1_checkpoint\"]\n\n[sub_resource type=\"RectangleShape2D\" id=\"RectangleShape2D_1\"]\nsize = Vector2(32, 32)\n\n[sub_resource type=\"Gradient\" id=\"Gradient_1\"]\noffsets = PackedFloat32Array(0, 0.5, 1)\ncolors = PackedColorArray(0.1, 0.2, 0.6, 1, 0.2, 0.9, 1, 1, 1, 1, 1, 1)\n\n[sub_resource type=\"Curve\" id=\"Curve_1\"]\nmax_value = 2.0\n_data = [Vector2(0, 1), 0.0, 0.0, 0, 0, Vector2(0.5, 1.8), 0.0, 0.0, 0, 0, Vector2(1, 2), 0.0, 0.0, 0, 0]\npoint_count = 3\n\n[node name=\"Checkpoint\" type=\"Area2D\"]\nscript = ExtResource(\"1_checkpoint\")\ncharge_gradient = SubResource(\"Gradient_1\")\nscale_curve = SubResource(\"Curve_1\")\nbeacon = NodePath(\"Beacon\")\ncharge_label = NodePath(\"ChargeLabel\")\n\n[node name=\"CollisionShape2D\" type=\"CollisionShape2D\" parent=\".\"]\nshape = SubResource(\"RectangleShape2D_1\")\n\n[node name=\"Beacon\" type=\"Sprite2D\" parent=\".\"]\n\n[node name=\"ChargeLabel\" type=\"Label\" parent=\".\"]\n\n[connection signal=\"body_entered\" from=\".\" to=\".\" method=\"_on_body_entered\"]\n"
}
output
The file /home/user/task/scenes/checkpoint.tscn has been updated successfully. (file state is current in your context , no need to Read it back)
Done. Both files are in place. **`scripts/checkpoint.gd`** , `Checkpoint` class with: - Exports `checkpoint_id` (0), `is_final_checkpoint` (false), `charge_gradient`, `scale_curve`, `beacon`, `charge_label`; public `is_active` (false). - Signals `activated(id: int)` and `level_complete`. - `apply_charge(t)` sets `beacon.modulate = charge_gradient.sample(t)` and `beacon.scale = Vector2.ONE * scale_curve.sample_baked(t)`. - `_on_body_entered` ignores non-`"Player"` bodies and already-lit checkpoints; on first player touch it activates, charges to full, writes the id into the label, emits `activated`, plus `level_complete` when final. - `reset()` clears `is_active`. **`scenes/checkpoint.tscn`** , `Area2D` root `Checkpoint` with the script attached, children `CollisionShape2D` (32×32 `RectangleShape2D`), `Beacon` (`Sprite2D`), `ChargeLabel` (`Label`). The `body_entered` signal is wired to `_on_body_entered`, and the exported `beacon`/`charge_label` reference the matching nodes. The authored resources: - **Gradient** , stops at 0.0 `(0.1,0.2,0.6)`, 0.5 `(0.2,0.9,1.0)`, 1.0 `(1.0,1.0,1.0)`. - **Curve** , points `(0,1.0)`, `(0.5,1.8)`, `(1.0,2.0)` with `max_value = 2.0` so the y-values aren't clamped (default max is 1.0); `sample_baked` returns those exact values at those positions.
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org
WARNING: Started the engine as `root`/superuser. This is a security risk, and subsystems like audio may not work correctly.
Set the environment variable `GODOT_SILENCE_ROOT_WARNING` to 1 to silence this warning.
     at: setup2 (main/main.cpp:3181)

VALIDATION_FAILED: beacon export must be wired to the Beacon Sprite2D in the scene

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_767761a8edd84bcc. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_767761a8edd84bcc · verifier authoritative; classifier explanatory.