Arm backend: aot_arm_compiler.py support BundleIO output file without a path

[zingo]

BundleIO output generation needed the specified output file name to be supplied with a folder, so if you wanted to output a file in the current folder you needed to add "./" in front of the file name like "./file.bpte" this change fixes this problem, the normal .pte generation already supported this.

cc @digantdesai @freddan80 @per @oscarandersson8218 @mansnils @Sebastian-Larsson @robell

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/18871

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❗ 1 Active SEVs

There are 1 currently active SEVs. If your PR is affected, please view them below:

• Rolling out OSDC (ARC) runners on pull workflow for PyTorch trunk commits

❌ 3 New Failures, 1 Cancelled Job, 1 Pending, 3 Unrelated Failures

As of commit 7725f0e with merge base 2c545f8 ():

NEW FAILURES - The following jobs have failed:

• trunk / test-torchao-huggingface-checkpoints (lfm2_5_1_2b, linux.arm64.2xlarge, executorch-ubuntu-22.04-g... / linux-job (gh)
  RuntimeError: Command docker exec -t 77c694a4af2ddb73151abbba27a33b3d297162be31199986a9d6e4768654a9df /exec failed with exit code 1
• trunk / test-torchao-huggingface-checkpoints (phi_4_mini, linux.arm64.2xlarge, executorch-ubuntu-22.04-gc... / linux-job (gh)
  RuntimeError: Command docker exec -t eb00cf668eccf63b35e25042b78cc9f756e66f839d1e1b8fec2968fdcc2d2522 /exec failed with exit code 1
• trunk / test-torchao-huggingface-checkpoints (qwen3_4b, linux.arm64.2xlarge, executorch-ubuntu-22.04-gcc1... / linux-job (gh)
  RuntimeError: Command docker exec -t d9e7436f2348d22a6dc5d5f05b881e8c64b85043480fae58afe515b328582bf6 /exec failed with exit code 1

CANCELLED JOB - The following job was cancelled. Please retry:

• trunk / test-models-linux-aarch64 (ic4, xnnpack-quantization-delegation, linux.arm64.2xlarge) / linux-job (gh)

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest-editable / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• trunk / unittest-release / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[Copilot]

Pull request overview

This PR fixes BundleIO .bpte output generation in the ARM AOT compiler so that specifying an output filename in the current working directory (e.g., file.bpte) works without requiring a ./ prefix.

Changes:

• Guard os.makedirs(output_dir, exist_ok=True) so it’s only called when os.path.dirname(output_name) is non-empty for BundleIO output saving.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.