[WIP] Fix failing GitHub Actions workflow build

[Copilot]

• Investigate the failing CI job (Job ID: 68446893456)
• Identify root cause: smoke-gemini.md fails to compile because GH_AW_GEMINI_BASE_CONFIG env var is set to a raw JSON object (starting with {) without YAML quoting, causing GitHub Actions schema validation to fail
• Fix FormatStepWithCommandAndEnv in engine_helpers.go to properly YAML-quote values that start with { or [
• Update the test for generateGeminiSettingsStep to verify YAML-safe env var encoding
• Run make recompile to verify the fix works
• Run make agent-finish to validate

Original prompt

Fix the failing GitHub Actions workflow build
Analyze the workflow logs, identify the root cause of the failure, and implement a fix.
Job ID: 68446893456
Job URL: https://github.com/github/gh-aw/actions/runs/23515517330/job/68446893456

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[Copilot]

Pull request overview

Fixes a GitHub Actions workflow YAML schema validation failure caused by emitting a raw JSON object into an env: value without YAML-safe quoting.

Changes:

• Update FormatStepWithCommandAndEnv to YAML-quote env var values that start with { or [ via a new yamlStringValue helper.
• Add unit tests covering YAML-safe quoting behavior and ensuring GitHub Actions expressions remain unquoted.
• Regenerate/update the locked Gemini smoke workflow to single-quote GH_AW_GEMINI_BASE_CONFIG values.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
pkg/workflow/engine_helpers.go	Ensures env values beginning with JSON flow indicators are emitted as YAML-safe strings.
pkg/workflow/engine_helpers_test.go	Adds coverage for yamlStringValue and YAML-safe env formatting behavior.
pkg/workflow/gemini_engine_test.go	Adds a regression test to assert Gemini settings step emits YAML-safe quoting for the JSON env var.
.github/workflows/smoke-gemini.lock.yml	Updates generated workflow output to single-quote the JSON config env var.

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[Copilot]

The docstring is inaccurate/confusing: it says values may be misinterpreted due to “other characters”, but the implementation only quotes when the first byte is '{' or '['. It also describes escaping single quotes as "(' becomes ”)", which is incorrect (YAML single-quote escaping is done by doubling the single quote: ''), and the current text uses a curly quote character.

Suggested change

	// If the value starts with a YAML flow indicator ('{' or '[') or other characters
	// that would cause it to be misinterpreted by YAML parsers, it wraps the value
	// in single quotes. Any embedded single quotes are escaped by doubling them (' becomes ”).
	// If the value starts with a YAML flow indicator ('{' or '['), it wraps the value
	// in single quotes. Any embedded single quotes are escaped by doubling them ('
	// becomes '').

[Copilot]

This assertion only checks for the presence of "GH_AW_GEMINI_BASE_CONFIG: '" and would still pass if the value is missing a closing quote (or otherwise malformed). Consider strengthening the test to verify that the env var value is properly single-quoted as a whole (e.g., the line starts with the key and contains a closing single quote at the end, or by parsing the generated YAML).

Suggested change

	// The JSON value must be single-quoted so YAML doesn't treat it as an object
	assert.Contains(t, content, "GH_AW_GEMINI_BASE_CONFIG: '", "JSON env var value must be single-quoted for valid YAML")
	// The JSON value must be single-quoted so YAML doesn't treat it as an object.
	// Find the specific line and verify the entire value is enclosed in single quotes.
	var envLine string
	for _, line := range strings.Split(content, "\n") {
	if strings.Contains(line, "GH_AW_GEMINI_BASE_CONFIG:") {
	envLine = line
	break
	}
	}
	require.NotEmpty(t, envLine, "GH_AW_GEMINI_BASE_CONFIG line should be present in step")
	trimmed := strings.TrimSpace(envLine)
	assert.True(t, strings.HasPrefix(trimmed, "GH_AW_GEMINI_BASE_CONFIG: '"),
	"JSON env var value must start with a single quote for valid YAML")
	assert.True(t, strings.HasSuffix(trimmed, "'"),
	"JSON env var value must end with a single quote for valid YAML")