Do not run CommandShell check during object creation

conf/experimental/megatron_bridge/test/b200/megatron_bridge_qwen_30b.toml

@@ -23,7 +23,6 @@ extra_container_mounts = []
 [[git_repos]]
 url = "https://github.com/NVIDIA-NeMo/Megatron-Bridge.git"
 commit = "v0.3.0"
-mount_as = "/opt/Megatron-Bridge"
 
 [cmd_args]
 gpu_type = "b200"

conf/experimental/megatron_bridge/test/gb200/megatron_bridge_qwen_30b.toml

@@ -23,7 +23,6 @@ extra_container_mounts = []
 [[git_repos]]
 url = "https://github.com/NVIDIA-NeMo/Megatron-Bridge.git"
 commit = "v0.3.0"
-mount_as = "/opt/Megatron-Bridge"
 
 [cmd_args]
 gpu_type = "gb200"

conf/experimental/megatron_bridge/test/gb300/megatron_bridge_qwen_30b.toml

@@ -23,7 +23,6 @@ extra_container_mounts = []
 [[git_repos]]
 url = "https://github.com/NVIDIA-NeMo/Megatron-Bridge.git"
 commit = "v0.3.0"
-mount_as = "/opt/Megatron-Bridge"
 
 [cmd_args]
 gpu_type = "gb300"
@@ -32,6 +31,7 @@ model_family_name = "qwen"
 model_recipe_name = "qwen3_30b_a3b"
 gpus_per_node = 4
 num_gpus = 8
+# mb = 4  # In case OOM, uncomment this for smaller micro-batch size
 domain = "llm"
 task = "pretrain"
 compute_dtype = "fp8_mx"

conf/experimental/megatron_bridge/test/h100/megatron_bridge_qwen_30b.toml

@@ -23,7 +23,6 @@ extra_container_mounts = []
 [[git_repos]]
 url = "https://github.com/NVIDIA-NeMo/Megatron-Bridge.git"
 commit = "v0.3.0"
-mount_as = "/opt/Megatron-Bridge"
 
 [cmd_args]
 gpu_type = "h100"

conf/experimental/megatron_bridge/test_scenario/megatron_bridge_qwen_30b.toml

@@ -1,5 +1,5 @@
 # SPDX-FileCopyrightText: NVIDIA CORPORATION & AFFILIATES
-# Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");

conf/experimental/megatron_bridge/test_scenario/megatron_bridge_r0.3.0_qwen_30b.toml

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: NVIDIA CORPORATION & AFFILIATES
+# Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name = "megatron_bridge_qwen_30b"
+
+[[Tests]]
+id = "megatron_bridge_qwen_30b"
+test_name = "megatron_bridge_qwen_30b"
+num_nodes = "2"
+
+  [[Tests.git_repos]]
+  url = "https://github.com/NVIDIA-NeMo/Megatron-Bridge.git"
+  commit = "r0.3.0"
+  mount_as = "/opt/Megatron-Bridge"
+  init_submodules = true
+
+  [Tests.extra_env_vars]
+  PYTHONPATH = "/opt/Megatron-Bridge/3rdparty/Megatron-LM:${PYTHONPATH}"

src/cloudai/_core/installables.py

@@ -1,5 +1,5 @@
 # SPDX-FileCopyrightText: NVIDIA CORPORATION & AFFILIATES
-# Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -91,6 +91,7 @@ class GitRepo(Installable, BaseModel):
 
     url: str
     commit: str
+    init_submodules: bool = False
     installed_path: Optional[Path] = None
     mount_as: Optional[str] = None
 

src/cloudai/_core/test_scenario.py

@@ -1,5 +1,5 @@
 # SPDX-FileCopyrightText: NVIDIA CORPORATION & AFFILIATES
-# Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -62,6 +62,7 @@ class TestRun:
     test: TestDefinition
     num_nodes: Union[int, list[int]]
     nodes: List[str]
+    exclude_nodes: List[str] = field(default_factory=list)
     output_path: Path = Path("")
     iterations: int = 1
     current_iteration: int = 0

src/cloudai/models/scenario.py

@@ -73,6 +73,13 @@ class TestRunModel(BaseModel):
     test_name: Optional[str] = None
     num_nodes: int | list[int] | None = None
     nodes: list[str] = Field(default_factory=list)
+    exclude_nodes: list[str] = Field(
+        default_factory=list,
+        description=(
+            "Hostnames to exclude from the resolved node list. "
+            "Supports Slurm range syntax, e.g. ['node-048', 'node-[101-104]']."
+        ),
+    )
     weight: int = 0
     iterations: int = 1
     sol: Optional[float] = None

src/cloudai/systems/kubernetes/kubernetes_installer.py

@@ -156,11 +156,23 @@ def _install_one_git_repo(self, item: GitRepo) -> InstallStatusResult:
             verify_res = self._verify_commit(item.commit, repo_path)
             if not verify_res.success:
                 return verify_res
+            if item.init_submodules:
+                res = self._init_submodules(repo_path)
+                if not res.success:
+                    return res
             item.installed_path = repo_path
             msg = f"Git repository already exists at {repo_path}."
             logging.debug(msg)
             return InstallStatusResult(True, msg)
 
+        res = self._clone_and_setup_repo(item, repo_path)
+        if not res.success:
+            return res
+
+        item.installed_path = repo_path
+        return InstallStatusResult(True)
+
+    def _clone_and_setup_repo(self, item: GitRepo, repo_path: Path) -> InstallStatusResult:
         res = self._clone_repository(item.url, repo_path)
         if not res.success:
             return res
@@ -172,7 +184,14 @@ def _install_one_git_repo(self, item: GitRepo) -> InstallStatusResult:
                 rmtree(repo_path)
             return res
 
-        item.installed_path = repo_path
+        if item.init_submodules:
+            res = self._init_submodules(repo_path)
+            if not res.success:
+                logging.error(f"Submodule init failed, removing cloned repository at {repo_path}")
+                if repo_path.exists():
+                    rmtree(repo_path)
+                return res
+
         return InstallStatusResult(True)
 
     def _install_python_executable(self, item: PythonExecutable) -> InstallStatusResult:
@@ -237,6 +256,14 @@ def _checkout_commit(self, commit_hash: str, path: Path) -> InstallStatusResult:
             return InstallStatusResult(False, f"Failed to checkout commit {commit_hash}: {result.stderr}")
         return InstallStatusResult(True)
 
+    def _init_submodules(self, path: Path) -> InstallStatusResult:
+        logging.debug(f"Initializing submodules in {path}")
+        submodule_cmd = ["git", "submodule", "update", "--init", "--recursive"]
+        result = subprocess.run(submodule_cmd, cwd=str(path), capture_output=True, text=True)
+        if result.returncode != 0:
+            return InstallStatusResult(False, f"Failed to initialize submodules: {result.stderr}")
+        return InstallStatusResult(True)
+
     def _verify_commit(self, ref: str, path: Path) -> InstallStatusResult:
         try:
             result = subprocess.run(["git", "rev-parse", "HEAD"], cwd=str(path), capture_output=True, text=True)

src/cloudai/systems/slurm/slurm_command_gen_strategy.py

@@ -424,6 +424,9 @@ def _append_nodes_related_directives(self, content: List[str]) -> Optional[Path]
 
         content.append(f"#SBATCH -N {num_nodes}")
 
+        if self.test_run.exclude_nodes:
+            content.append(f"#SBATCH --exclude={','.join(self.test_run.exclude_nodes)}")
+
         return None
 
     def _format_env_vars(self, env_vars: Dict[str, Any]) -> str:
@@ -465,12 +468,17 @@ def get_cached_nodes_spec(self) -> tuple[int, list[str]]:
                 str(self.test_run.step),
                 str(self.test_run.nnodes),
                 ",".join(self.test_run.nodes),
+                ",".join(self.test_run.exclude_nodes),
             ]
         )
 
         if cache_key in self._node_spec_cache:
             logging.debug(f"Using cached node allocation for {cache_key}: {self._node_spec_cache[cache_key]}")
             return self._node_spec_cache[cache_key]
 
-        self._node_spec_cache[cache_key] = self.system.get_nodes_by_spec(self.test_run.nnodes, self.test_run.nodes)
+        num_nodes, node_list = self.system.get_nodes_by_spec(
+            self.test_run.nnodes, self.test_run.nodes, exclude_nodes=self.test_run.exclude_nodes or None
+        )
+
+        self._node_spec_cache[cache_key] = (num_nodes, node_list)
         return self._node_spec_cache[cache_key]

src/cloudai/systems/slurm/slurm_installer.py

@@ -209,11 +209,23 @@ def _install_one_git_repo(self, item: GitRepo) -> InstallStatusResult:
             verify_res = self._verify_commit(item.commit, repo_path)
             if not verify_res.success:
                 return verify_res
+            if item.init_submodules:
+                res = self._init_submodules(repo_path)
+                if not res.success:
+                    return res
             item.installed_path = repo_path
             msg = f"Git repository already exists at {repo_path}."
             logging.debug(msg)
             return InstallStatusResult(True, msg)
 
+        res = self._clone_and_setup_repo(item, repo_path)
+        if not res.success:
+            return res
+
+        item.installed_path = repo_path
+        return InstallStatusResult(True)
+
+    def _clone_and_setup_repo(self, item: GitRepo, repo_path: Path) -> InstallStatusResult:
         res = self._clone_repository(item.url, repo_path)
         if not res.success:
             return res
@@ -225,7 +237,14 @@ def _install_one_git_repo(self, item: GitRepo) -> InstallStatusResult:
                 rmtree(repo_path)
             return res
 
-        item.installed_path = repo_path
+        if item.init_submodules:
+            res = self._init_submodules(repo_path)
+            if not res.success:
+                logging.error(f"Submodule init failed, removing cloned repository at {repo_path}")
+                if repo_path.exists():
+                    rmtree(repo_path)
+                return res
+
         return InstallStatusResult(True)
 
     def _install_python_executable(self, item: PythonExecutable) -> InstallStatusResult:
@@ -290,6 +309,14 @@ def _checkout_commit(self, commit_hash: str, path: Path) -> InstallStatusResult:
             return InstallStatusResult(False, f"Failed to checkout commit {commit_hash}: {result.stderr}")
         return InstallStatusResult(True)
 
+    def _init_submodules(self, path: Path) -> InstallStatusResult:
+        logging.debug(f"Initializing submodules in {path}")
+        submodule_cmd = ["git", "submodule", "update", "--init", "--recursive"]
+        result = subprocess.run(submodule_cmd, cwd=str(path), capture_output=True, text=True)
+        if result.returncode != 0:
+            return InstallStatusResult(False, f"Failed to initialize submodules: {result.stderr}")
+        return InstallStatusResult(True)
+
     def _verify_commit(self, ref: str, path: Path) -> InstallStatusResult:
         try:
             result = subprocess.run(["git", "rev-parse", "HEAD"], cwd=str(path), capture_output=True, text=True)