Fix Codex lock compiler: move --model flag after exec subcommand by Copilot · Pull Request #33841 · github/gh-aw

Copilot · 2026-05-21T18:41:53Z

The Codex lock compiler was emitting the --model flag before the exec subcommand. Codex CLI treats flags in that position as global options and silently ignores them, causing all custom model selections to fall back to the default.

Before (broken):

codex ${GH_AW_MODEL_AGENT_CODEX:+--model "$GH_AW_MODEL_AGENT_CODEX" }exec -c web_search="disabled" ...

After (fixed):

codex exec${GH_AW_MODEL_AGENT_CODEX:+ --model "$GH_AW_MODEL_AGENT_CODEX"} -c web_search="disabled" ...

Changes

codex_engine.go: Reorder both format strings (harness and non-harness paths) so exec precedes modelParam; adjust shell expansion from trailing-space to leading-space form (${VAR:+ --model "$VAR"}) so spacing is correct in both the set and unset cases.
model_env_vars_test.go: Update expected pattern to match new format; add regression test TestCodexModelFlagPositionAfterExec that asserts exec appears before the model expansion in the generated command.
engine_includes_test.go: Update assertion from "codex ${" → "codex exec${".
testdata/TestWasmGolden_AllEngines/codex.golden: Update snapshot.
.changeset/patch-fix-codex-model-flag.md: Update description to accurately describe the position fix.

pr-sous-chef: requested branch update from run https://github.com/github/gh-aw/actions/runs/26248288802

Generated by 👨‍🍳 PR Sous Chef · ● 2.6M · ◷

Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot

Pull request overview

Fixes Codex CLI invocation generation so the optional --model flag is emitted after the exec subcommand (so Codex treats it as a subcommand flag rather than a global flag and doesn’t ignore it).

Changes:

Reordered Codex command construction (harness and non-harness) to codex exec … followed by the conditional model expansion.
Updated tests and golden snapshots to match the new command shape.
Updated the changeset text describing the fix.

Show a summary per file

File	Description
`pkg/workflow/codex_engine.go`	Reorders generated Codex CLI command so `exec` precedes the conditional `--model` expansion.
`pkg/workflow/model_env_vars_test.go`	Updates expected model expansion formatting; adds a regression test for `exec` vs `--model` ordering.
`pkg/workflow/engine_includes_test.go`	Updates lock-file assertion to match `codex exec${...}` pattern.
`pkg/workflow/testdata/TestWasmGolden_AllEngines/codex.golden`	Updates snapshot to reflect corrected Codex command ordering.
`.github/workflows/pr-code-quality-reviewer.lock.yml`	Lock file regenerated; notably drops `shared/reporting.md` runtime-import.
`.changeset/patch-fix-codex-model-flag.md`	Updates release note describing the Codex model-flag positioning fix.

Copilot's findings

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Files reviewed: 6/6 changed files
Comments generated: 3

+	// Find the model shell expansion pattern in the generated command
+	modelPattern := "${" + constants.EnvVarModelAgentCodex + ":+"
+	modelIdx := strings.Index(stepsContent, modelPattern)
+	if modelIdx == -1 {
+		t.Fatalf("Model expansion pattern '%s' not found in steps:\n%s", modelPattern, stepsContent)
+	}
+
+	// Find "exec" in the generated command (look for the last occurrence before the model pattern
+	// to handle multi-line step content)
+	execIdx := strings.LastIndex(stepsContent[:modelIdx], "exec")
+	if execIdx == -1 {
+		t.Errorf("'exec' subcommand must appear before the model flag '%s' in the generated command.\n"+
+			"This indicates the model flag is placed before 'exec', causing Codex to ignore it.\n"+
+			"Got:\n%s", modelPattern, stepsContent)


 ---

-Fixed the Codex engine to pass the model via `--model` instead of the deprecated TOML override so engine model selection works with newer Codex CLI versions.
+Fixed the Codex engine to emit `codex exec --model "$VAR"` instead of `codex "$VAR"exec` so the model flag is correctly positioned after the `exec` subcommand. Previously the model parameter was placed before `exec`, causing Codex CLI to ignore it and silently fall back to the default model.


          cat "${RUNNER_TEMP}/gh-aw/prompts/github_mcp_tools_with_safeoutputs_prompt.md"
          if [ "$GITHUB_EVENT_NAME" = "issue_comment" ] && [ -n "$GH_AW_IS_PR_COMMENT" ] || [ "$GITHUB_EVENT_NAME" = "pull_request_review_comment" ] || [ "$GITHUB_EVENT_NAME" = "pull_request_review" ]; then
            cat "${RUNNER_TEMP}/gh-aw/prompts/pr_context_prompt.md"
          fi
-          cat << 'GH_AW_PROMPT_03f9bc9676534c1b_EOF'
+          cat << 'GH_AW_PROMPT_4f5501639950bddf_EOF'
          </system>
-          {{#runtime-import .github/workflows/shared/reporting.md}}
          {{#runtime-import .github/workflows/shared/otlp.md}}
          {{#runtime-import .github/workflows/shared/github-guard-policy.md}}
          {{#runtime-import .github/workflows/shared/pr-code-review-config.md}}
          {{#runtime-import .github/workflows/shared/noop-reminder.md}}
          {{#runtime-import .github/workflows/pr-code-quality-reviewer.md}}


github-actions · 2026-05-21T19:35:50Z

``
Please rerun checks after the flag-position fix and confirm the branch update cleared the remaining issues.

Generated by 👨‍🍳 PR Sous Chef · ● 2.6M · ◷

lpcox · 2026-05-21T20:00:13Z

@copilot address review feedback and merge main

…k-compiler-flag-position Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

…geset, revert unintended lock file, merge main Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot · 2026-05-21T20:14:15Z

@copilot address review feedback and merge main

Done. Three changes addressed from the review:

Regression test (model_env_vars_test.go): Changed the search string from "exec" to "codex exec" so the test can't pass on a false positive from GH_AW_NODE_EXEC.
Changeset description (.changeset/patch-fix-codex-model-flag.md): Updated to accurately show the old broken shell expansion form (codex ${VAR:+--model "$VAR" }exec) rather than the misleading codex "$VAR"exec.
Unintentional lock file change: Reverted .github/workflows/pr-code-quality-reviewer.lock.yml to its pre-PR state.

Also merged main (with conflict resolved in the golden snapshot — main had a pre-existing inconsistency in that file, so I regenerated it from the current source).

pelikhan · 2026-05-21T20:35:03Z

@copilot lint go

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot · 2026-05-21T20:43:53Z

@copilot lint go

Fixed in the latest commit. The strings.Index in model_env_vars_test.go was flagged by the modernize linter and replaced with strings.Cut — beforeModel (the text before the model pattern) is used directly instead of stepsContent[:modelIdx], which is both cleaner and avoids the separate index variable. Linter now reports 0 issues.

Initial plan

61970b4

Copilot AI assigned Copilot and lpcox May 21, 2026

Copilot started work on behalf of lpcox May 21, 2026 18:42 View session

Copilot AI linked an issue May 21, 2026 that may be closed by this pull request

Codex lock compiler places --model flag before exec subcommand #33838

Closed

Copilot AI and others added 2 commits May 21, 2026 18:51

Initial plan for fixing Codex model flag position

d5400c7

Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Fix Codex model flag position: move --model after exec subcommand

dc47e4d

Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix model flag position in Codex lock compiler command~~ Fix Codex lock compiler: move --model flag after exec subcommand May 21, 2026

Copilot AI requested a review from lpcox May 21, 2026 19:01

Copilot finished work on behalf of lpcox May 21, 2026 19:01

pelikhan marked this pull request as ready for review May 21, 2026 19:03

Copilot AI review requested due to automatic review settings May 21, 2026 19:03

Copilot started reviewing on behalf of pelikhan May 21, 2026 19:04 View session

Copilot AI reviewed May 21, 2026

View reviewed changes

Copilot started work on behalf of lpcox May 21, 2026 20:00 View session

Copilot AI and others added 2 commits May 21, 2026 20:10

Merge remote-tracking branch 'origin/main' into copilot/fix-codex-loc…

f966128

…k-compiler-flag-position Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Address review feedback: fix regression test specificity, update chan…

25d667e

…geset, revert unintended lock file, merge main Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot finished work on behalf of lpcox May 21, 2026 20:14

Copilot started work on behalf of pelikhan May 21, 2026 20:35 View session

fix: simplify strings.Index to strings.Cut per modernize linter

63faf44

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot finished work on behalf of pelikhan May 21, 2026 20:44

Copilot AI requested a review from pelikhan May 21, 2026 20:44

pelikhan merged commit 61f44a9 into main May 21, 2026

pelikhan deleted the copilot/fix-codex-lock-compiler-flag-position branch May 21, 2026 20:45

github-actions Bot mentioned this pull request May 21, 2026

Smoke Test: Claude - 26254375762 #33868

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Fix Codex lock compiler: move --model flag after exec subcommand#33841

Fix Codex lock compiler: move --model flag after exec subcommand#33841
pelikhan merged 6 commits into
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Pull request overview

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