Restore resBuildResult fields for failed builds

[edolstra]

Motivation

Context

Summary by CodeRabbit

• Bug Fixes

  • Made JSON build-failure logging payloads more consistent so logged results reliably reflect failure details.
  • Ensured timed-out builds record timeout status and error message in JSON logs.

• Tests

  • Added functional test coverage verifying JSON logging for timeout scenarios.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 6278d5f3-8dd1-4d65-b988-3e48312cb52d

📥 Commits

Reviewing files that changed from the base of the PR and between 3853269 and b3ca704.

📒 Files selected for processing (3)

• src/libstore/build/derivation-building-goal.cc
• src/libstore/build/substitution-goal.cc
• tests/functional/logging.sh

✅ Files skipped from review due to trivial changes (1)

• src/libstore/build/substitution-goal.cc

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📝 Walkthrough

Walkthrough

This PR refactors goal failure logging across two build system components and adds test coverage. Failure result JSON payloads now use structured intermediate variables instead of inline exceptions, and a functional test verifies JSON logging of timed-out builds.

Changes

Build Failure JSON Logging Refactor

Layer / File(s)	Summary
Failure Result JSON Refactor src/libstore/build/derivation-building-goal.cc, src/libstore/build/substitution-goal.cc	DerivationBuildingGoal::doneFailure() and PathSubstitutionGoal::doneFailure() now extract build results into local variables and pass them directly to KeyedBuildResult for JSON serialization, removing inline exception embedding from the logger payload. Both handlers assign Goal::doneFailure() result to a local variable for return.
JSON Logging Test Coverage tests/functional/logging.sh	New functional test verifies that JSON logs correctly record timed-out builds with status:TimedOut and matching error messages.

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🎯 2 (Simple) | ⏱️ ~12 minutes

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🐰 The logs once held exceptions raw,
Now structured results flow through the door,
With timeouts captured in JSON's jaw—
Failures logged cleaner than ever before! 🎉

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly matches the main objective of the changeset: restoring resBuildResult fields for failed builds in the build and substitution goal files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch eelcodolstra/nix-391

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@tests/functional/logging.sh`:
- Line 44: The rm invocation uses an unquoted expansion (rm $TEST_ROOT/log.json)
which can suffer word-splitting/globbing; update the rm call to use a quoted
expansion of the TEST_ROOT variable with the filename (for example use a quoted
${TEST_ROOT}/log.json or "$TEST_ROOT/log.json") so the path is treated as a
single argument and globbing is prevented.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 6c2d361a-87d1-4f2f-9374-275120ae7ecc

📥 Commits

Reviewing files that changed from the base of the PR and between a09ec4c and 3853269.

📒 Files selected for processing (3)

• src/libstore/build/derivation-building-goal.cc
• src/libstore/build/substitution-goal.cc
• tests/functional/logging.sh

[github-actions]

🚀 Deployed on https://69fcefd1cd58121a43facc8e--determinate-nix.netlify.app