ARCHIVED TRAINING / rochacbruno/dynaconf

rochacbruno__dynaconf-290

This is a preserved training example. Membership in the current training wave has not been verified.

Problem statement

[bug] RuntimeError: dictionary changed size during iteration when using @del within dynaconf_merge logic
**Describe the bug**
The following [line](https://github.com/rochacbruno/dynaconf/blob/25fed5dc27d1dd78c368d7464f7d160b46aa1d24/dynaconf/utils/__init__.py#L49
) is bugged, changing dict size during iteration, via pop() leads to 

```
RuntimeError: dictionary changed size during iteration
```

**To Reproduce**
You can run following python code which is assumed to be very simple interpretation of the code line above:
```
new = {"a": 1}

for k, v in new.items():
    new.pop(k, None)
```

1. To reproduce it with `dynaconf`, use following config.yaml
```
default:
  options:
    A: 1
    B: 2
development:
  options:
    dynaconf_merge:
      B: "@del"
```

**Expected behavior**
No RuntimeError, key marked with `@del` is removed from merge result

Training membership

opd_e4b_pure_v6a opd_e4b_pure_v6b opd_e4b_pure_v7 opd_e4b_pure_v7b

Task issues extracted from preserved verified_rft_messages training examples. This is not a verified current RL wave manifest.

Task and snapshot provenance

Snapshot captured 2026-11-12T17:06:59.476467+00:00 · Autoresearch-Arena/gemma-4-developer-agent

{
  "datasets": [
    "opd_e4b_pure_v6a",
    "opd_e4b_pure_v6b",
    "opd_e4b_pure_v7",
    "opd_e4b_pure_v7b"
  ],
  "examples": 12,
  "instance_id": "rochacbruno__dynaconf-290",
  "problem_statement": "[bug] RuntimeError: dictionary changed size during iteration when using @del within dynaconf_merge logic\n**Describe the bug**\r\nThe following [line](https://github.com/rochacbruno/dynaconf/blob/25fed5dc27d1dd78c368d7464f7d160b46aa1d24/dynaconf/utils/__init__.py#L49\r\n) is bugged, changing dict size during iteration, via pop() leads to \r\n\r\n```\r\nRuntimeError: dictionary changed size during iteration\r\n```\r\n\r\n**To Reproduce**\r\nYou can run following python code which is assumed to be very simple interpretation of the code line above:\r\n```\r\nnew = {\"a\": 1}\r\n\r\nfor k, v in new.items():\r\n    new.pop(k, None)\r\n```\r\n\r\n1. To reproduce it with `dynaconf`, use following config.yaml\r\n```\r\ndefault:\r\n  options:\r\n    A: 1\r\n    B: 2\r\ndevelopment:\r\n  options:\r\n    dynaconf_merge:\r\n      B: \"@del\"\r\n```\r\n\r\n**Expected behavior**\r\nNo RuntimeError, key marked with `@del` is removed from merge result",
  "repo": "rochacbruno/dynaconf",
  "source": "v2/experiments/train_data/opd_e4b_pure_v6a/verified_rft_messages.jsonl",
  "source_sha256": "f045b7ca5b3883a1e2eaee81e1c02a4a1b53dd7b7b36e98bacb2ba5823a15148"
}

{
  "captured_at": "2026-11-12T17:06:59.476467+00:00",
  "membership": "archived training",
  "membership_evidence": "Task issues extracted from preserved verified_rft_messages training examples. This is not a verified current RL wave manifest.",
  "name": "Preserved post-training task archive",
  "source": "Autoresearch-Arena/gemma-4-developer-agent",
  "source_revision": "016496de222aaafca0d4ee4c18efc63ba616f76e",
  "sources": [
    {
      "path": "v2/experiments/train_data/opd_e4b_cispo_v5/verified_rft_messages.jsonl",
      "sha256": "a43610ad0dfb6ace95375cfae09000f41afc0338cc925af870a4ade7a9b20c4c"
    },
    {
      "path": "v2/experiments/train_data/opd_e4b_hybrid_v3/verified_rft_messages.jsonl",
      "sha256": "bd326303eb127e8e5e08f03daf97bb88d79d19709d59f3f93f348bc56686a8df"
    },
    {
      "path": "v2/experiments/train_data/opd_e4b_onpolicy_v3/verified_rft_messages.jsonl",
      "sha256": "960c680e797e823a0d3a22f4b1d5ef60a72971373d703b877340b0c9126aaf68"
    },
    {
      "path": "v2/experiments/train_data/opd_e4b_pure_v6a/verified_rft_messages.jsonl",
      "sha256": "f045b7ca5b3883a1e2eaee81e1c02a4a1b53dd7b7b36e98bacb2ba5823a15148"
    },
    {
      "path": "v2/experiments/train_data/opd_e4b_pure_v6b/verified_rft_messages.jsonl",
      "sha256": "0f62460a9706eea5e1605255896f191ab00cb5706c5f1f2e1c293e9a718218dc"
    },
    {
      "path": "v2/experiments/train_data/opd_e4b_pure_v7/verified_rft_messages.jsonl",
      "sha256": "e37f7bd675322f3f81500b73559d60d5f602ca0537bf19f5cb06332c728c7b72"
    },
    {
      "path": "v2/experiments/train_data/opd_e4b_pure_v7b/verified_rft_messages.jsonl",
      "sha256": "b864bdc8695183433eef6e31cb8d33fad44ba3aded2170c1ade4ad5b2944ce23"
    },
    {
      "path": "v2/experiments/train_data/opd_e4b_self_audit_v4/verified_rft_messages.jsonl",
      "sha256": "0026023745afb8f3dc1c176dc7f7171157b4ad5a66656b524af218e8e19ceee6"
    },
    {
      "path": "v2/experiments/train_data/rft_e4b_aligned_v2/verified_rft_messages.jsonl",
      "sha256": "92a4515fee9d152b0d4c510ee3ce4caaaffe2003ba7584469f8027f174aab18c"
    },
    {
      "path": "v2/experiments/train_data/rft_v1/verified_rft_messages.jsonl",
      "sha256": "a42453ccd7ac7680b0a03865e8e7080bc8bf74c8d9d193b440c441ed46f8512b"
    },
    {
      "path": "v2/experiments/train_data/rft_v2/verified_rft_messages.jsonl",
      "sha256": "18f4b3bd7e651f83c6acab479c9475e3fa50dc652a384f309e97146983ac85ba"
    }
  ]
}