fix(ci): AUT-1100 keep verl and MCore on main

.github/workflows/verl_ci/run_megatron_deepseek.sh

@@ -29,6 +29,7 @@ trap cleanup EXIT
 pip3 install git+https://github.com/NVIDIA-NeMo/Megatron-Bridge.git@main --no-deps --no-build-isolation
 pip3 install git+https://github.com/NVIDIA/Megatron-LM.git@main --no-deps --no-build-isolation
 pip3 install "nvidia-modelopt[torch]>=0.37.0"
+pip3 install "transformers==5.12.1"
 ## cd to verl checkout root
 pip3 install -r requirements-test.txt
 pip3 install -r requirements.txt

.github/workflows/verl_ci/run_megatron_moe_expert_parallel.sh

@@ -28,6 +28,7 @@ trap cleanup EXIT
 pip3 install git+https://github.com/NVIDIA-NeMo/Megatron-Bridge.git@main --no-deps --no-build-isolation
 pip3 install git+https://github.com/NVIDIA/Megatron-LM.git@main --no-deps --no-build-isolation
 pip3 install "nvidia-modelopt[torch]>=0.37.0"
+pip3 install "transformers==5.12.1"
 ## cd to verl checkout root
 pip3 install -r requirements-test.txt
 pip3 install -r requirements.txt

.github/workflows/verl_ci/run_megatron_qwen3.sh

@@ -28,6 +28,7 @@ trap cleanup EXIT
 pip3 install git+https://github.com/NVIDIA-NeMo/Megatron-Bridge.git@main --no-deps --no-build-isolation
 pip3 install git+https://github.com/NVIDIA/Megatron-LM.git@main --no-deps --no-build-isolation
 pip3 install "nvidia-modelopt[torch]>=0.37.0"
+pip3 install "transformers==5.12.1"
 ## cd to verl checkout root
 pip3 install -r requirements-test.txt
 pip3 install -r requirements.txt

src/megatron/bridge/data/builders/energon.py

@@ -22,7 +22,6 @@
 from transformers import AutoProcessor, AutoTokenizer, Qwen3VLProcessor
 
 from megatron.bridge.data.base import DataloaderConfig, DatasetBuildContext, validate_declarative_mapping
-from megatron.bridge.data.energon.base_energon_datamodule import EnergonMultiModalDataModule
 from megatron.bridge.models.hf_pretrained.utils import is_safe_repo
 
 
@@ -289,6 +288,8 @@ def __init__(self, config: EnergonDatasetConfig) -> None:
 
     def build(self, context: DatasetBuildContext) -> tuple[Any | None, Any | None, None]:
         """Build requested Energon train and validation iterators."""
+        from megatron.bridge.data.energon.base_energon_datamodule import EnergonMultiModalDataModule
+
         assert self.config.path is not None
         build_train = context.train_samples > 0
         build_validation = self.config.do_validation and context.valid_samples > 0

tests/unit_tests/data/builders/test_energon_builder.py

@@ -28,6 +28,7 @@
     QwenVLEnergonTaskEncoderConfig,
     build_energon_task_encoder,
 )
+from megatron.bridge.data.energon import base_energon_datamodule
 from megatron.bridge.training.config import ConfigContainer
 from megatron.bridge.training.utils.omegaconf_utils import process_config_with_overrides
 
@@ -226,7 +227,7 @@ def test_builder_honors_requested_splits_and_reuses_runtime_encoder(monkeypatch:
     datamodule.val_dataloader.return_value = ["validation"]
     datamodule_cls = MagicMock(return_value=datamodule)
     monkeypatch.setattr("megatron.bridge.data.builders.energon.build_energon_task_encoder", build_encoder)
-    monkeypatch.setattr("megatron.bridge.data.builders.energon.EnergonMultiModalDataModule", datamodule_cls)
+    monkeypatch.setattr(base_energon_datamodule, "EnergonMultiModalDataModule", datamodule_cls)
 
     train, validation, test = EnergonDatasetBuilder(config).build(
         DatasetBuildContext(train_samples=10, valid_samples=5, test_samples=3)
@@ -248,7 +249,8 @@ def test_builder_skips_unrequested_validation(monkeypatch: pytest.MonkeyPatch):
     datamodule.train_dataloader.return_value = []
     monkeypatch.setattr("megatron.bridge.data.builders.energon.build_energon_task_encoder", lambda _: object())
     monkeypatch.setattr(
-        "megatron.bridge.data.builders.energon.EnergonMultiModalDataModule",
+        base_energon_datamodule,
+        "EnergonMultiModalDataModule",
         MagicMock(return_value=datamodule),
     )
 

tests/unit_tests/data/test_module_layout.py

@@ -1,6 +1,8 @@
 # Copyright (c) 2026, NVIDIA CORPORATION.  All rights reserved.
 
 import importlib
+import subprocess
+import sys
 
 import pytest
 
@@ -23,3 +25,16 @@
 def test_removed_internal_data_modules_have_no_compatibility_shims(module_name):
     with pytest.raises(ModuleNotFoundError):
         importlib.import_module(module_name)
+
+
+def test_training_config_import_does_not_require_energon():
+    code = "import sys; sys.modules['megatron.energon'] = None; import megatron.bridge.training.config"
+    result = subprocess.run(
+        [sys.executable, "-c", code],
+        capture_output=True,
+        text=True,
+        timeout=180,
+        check=False,
+    )
+
+    assert result.returncode == 0, result.stderr or result.stdout