```trtexec``` fails at the end if ```--saveEngine``` path is invalid or unwritable

[PierreMarieCurie]

Description

When running trtexec with the --saveEngine flag pointing to an invalid or unwritable path, the tool proceeds to parse the ONNX model and build the engine. However, it only fails at the very end when attempting to serialize the engine, wasting time and resources.

This issue is created to introduce the following pull request: #4449

Environment

This issue should occur regardless of the system configuration.

Steps To Reproduce

trtexec --onnx=model.onnx --saveEngine=/invalid_path/engine.trt

[AditiThirdEye]

I've also submitted an implementation for this: #4675

My approach validates the --saveEngine path immediately after parsing by checking parent directory existence and testing write permissions via a temporary file. Happy to defer to #4449 if maintainers prefer that implementation, or collaborate on merging the best aspects of both.

[PierreMarieCurie]

Hello @AditiThirdEye ,
From what I can see, both implementations are functionally identical. Please let me know if I’m missing something.

[AditiThirdEye]

Hi @PierreMarieCurie, thanks for taking a look!

You're right - I reviewed both implementations and they are essentially the same approach (checking parent directory existence + testing write permissions via temp file).

Since your PR #4449 was submitted first, I'm happy to close mine and defer to yours. No need to duplicate effort!