Handle the case when the benchmark script produces an empty CSV

[motus]

Pull Request

Title

Handle the case when a script invoked by local_env fails silently (i.e., with error code 0) and produces an empty metrics CSV file.

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Description

• check if the metrics input file is empty;
• make sure the input CSV file contains all required metrics columns.
• add unit test for the case
• make local env unit tests a bit more flexible to check other cases like this one

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Type of Change

• 🛠️ Bug fix

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Testing

added a new unit test to cover the case

Closes #998

[Copilot]

Pull Request Overview

This PR handles edge cases where benchmark scripts produce empty CSV files despite returning successful exit codes. The changes ensure robust handling of empty metrics files and improve test infrastructure to verify different failure scenarios.

• Added validation to check for empty CSV files and mark trials as failed
• Enhanced test framework to support flexible status checking for different test scenarios
• Fixed column specification in DataFrame creation for optimizer

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
local_env.py	Added check for empty CSV files and return FAILED status
init.py	Enhanced test helper function to support flexible status expectations
local_env_test.py	Added new test case for empty CSV file scenario
local_env_vars_test.py	Updated test call to use keyword arguments
mlos_core_optimizer.py	Fixed DataFrame creation with explicit column specification

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