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 validation failed with: 'VALIDATION_FAILED: beacon export must be wired to the Beacon Sprite2D in the scene'. The test (lines 48-52 of test.gd) checks `cp.get("beacon")` which returned null, meaning the node reference was not properly wired. The agent wrote the scene file with `beacon = NodePath("Beacon")` and `charge_label = NodePath("ChargeLabel")` syntax, but this did not correctly establish the node references that the test expects.
Root causeThe agent created a functionally reasonable scene structure but used incorrect Godot scene file syntax for wiring exported node references. The NodePath syntax in the TSCN file did not properly establish the reference that cp.get("beacon") could retrieve, likely requiring different TSCN syntax or an alternative approach to node reference binding.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
17 tool calls · 3 tool types · 17 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 both files for the checkpoint beacon.
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 when the player lights a checkpoint flagged as final.\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
Write
{
  "file_path": "/home/user/task/scenes/checkpoint.tscn",
  "content": "[gd_scene load_steps=5 format=3 uid=\"uid://b0qx2checkpoint01\"]\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
<tool_use_error>File has not been read yet. Read it first before writing to it.</tool_use_error>

[error] tool reported failure
Files already exist , let me read them first.
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
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
Both are stubs. I'll overwrite them with the full implementation.
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 when the player lights a checkpoint flagged as final.\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)
Write
{
  "file_path": "/home/user/task/scenes/checkpoint.tscn",
  "content": "[gd_scene load_steps=5 format=3 uid=\"uid://b0qx2checkpoint01\"]\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 implemented. **`scripts/checkpoint.gd`** , the `Checkpoint` class extending `Area2D`: - Exported `checkpoint_id` (int, 0), `is_final_checkpoint` (bool, false), public `is_active` (bool, false). - Exported `charge_gradient`, `scale_curve`, `beacon`, `charge_label`. - `apply_charge(t)` sets `beacon.modulate` from the gradient sample and `beacon.scale` from `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(checkpoint_id)`, and emits `level_complete` if final. - `reset()` re-arms it. - Signals `activated(id: int)` and `level_complete`. **`scenes/checkpoint.tscn`** , `Checkpoint` (`Area2D`) root with the script attached, a `CollisionShape2D` (32×32 `RectangleShape2D`), a `Beacon` (`Sprite2D`), and a `ChargeLabel` (`Label`). The `beacon`/`charge_label` exports are wired to those nodes, and `body_entered` is connected to `_on_body_entered`. Two authoring details worth flagging: - The `Curve` needs `max_value = 2.0` , Godot's default `Curve` max is `1.0`, which would clamp the `1.8`/`2.0` stops. I set it so `sample_baked` returns the intended values. - The scene has no texture on `Beacon`, so it won't render anything visible until you assign one; `modulate`/`scale` still drive correctly. Let me know if you want a placeholder texture wired in.
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_af9f29916e3245df. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_af9f29916e3245df · verifier authoritative; classifier explanatory.