[naokihaba]

Context

• resolves User fish functions named like built-ins break the vp wrapper and vpr completion in env.fish #3128

When a user defines a fish function with the name of a built-in, env.fish calls the user function instead of the built-in. With a user count function, vp env use reports success, but the Node.js version does not change.

The fish documentation for function warns about this case. It says that a function with the name of a built-in often causes problems "in scripts written by others". env.fish is such a script.

This PR adds builtin to each built-in that env.fish calls: count, math, contains, complete, commandline, and source. builtin skips functions and runs only the built-in. #3123 did the same for Nushell with the % sigil.

This PR does not change the vp completion. clap_complete registers it with bare complete and commandline, so env.fish cannot protect it. fish's own completions also call bare commandline.

# fish 4.9.3, vp built from 09961cfa5
# $R is a temporary VP_HOME. A line that starts with > is a command. [exit N] is the exit status of the command above it.

$ VP_HOME=$R VP_SELF_SETUP_NO_MODIFY_PATH=1 ./target/debug/vp env setup --refresh
[exit 0]
$ sed 's/builtin //g' $R/env.fish > $R/env-old.fish
$ diff $R/env-old.fish $R/env.fish | grep -c '^>'
14

## env-old.fish
> function count; echo 0; end
[exit 0]
> source env-old.fish
[exit 0]
> set -gx VP_NODE_VERSION 18.20.0
[exit 0]
> vp env use 20.20.2
Installing Node.js v20.20.2...
Using Node.js v20.20.2 (resolved from 20.20.2)
[exit 0]
> echo VP_NODE_VERSION=$VP_NODE_VERSION
VP_NODE_VERSION=18.20.0
[exit 0]
> node --version
v18.20.0
[exit 0]

## env.fish
> function count; echo 0; end
[exit 0]
> source env.fish
[exit 0]
> set -gx VP_NODE_VERSION 18.20.0
[exit 0]
> vp env use 20.20.2
Using Node.js v20.20.2 (resolved from 20.20.2)
[exit 0]
> echo VP_NODE_VERSION=$VP_NODE_VERSION
VP_NODE_VERSION=20.20.2
[exit 0]
> node --version
v20.20.2
[exit 0]

[naokihaba]

@codex review

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-11-04T15:04:02.507618Z	09961cf	Manual request

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[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Nice work!

Reviewed commit: 09961cfa54

ℹ️ About Codex in GitHub

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• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[naokihaba]

Maybe we should wait for #3354 to be merged first and then do a final check on this PR just to be safe.

[naokihaba]

I merged main into this branch to get #3354, and then checked commit aa317daba on macOS with fish 4.9.3.

All 3 command_env_fish snapshot cases pass: setup, use, and shadowed_builtins. The 2 unit tests from #3354 also pass: test_parse_task_completion_lines and test_sanitize_task_current_prefix.

I also ran a manual check with the debug vp two times. The first run had no user functions. The second run had user functions that shadow count, math, contains, and source, as in #3128. The two runs gave the same result:

• env.fish loads without errors.
• vp env use and vp -C . env use set VP_NODE_VERSION, and vp env use --help does not change it.
• The vpr completion does not show the comment keys // and # Scripts for docs #.
• Each vpr completion candidate shows its task command as the description.
• The input test\:u matches test:unit.
• env.fish does not replace the user's count function.

$ builtin source <tmp>/env.fish
  -> status=0
$ vp env use 20.20.2 --no-install
Using Node.js v20.20.2 (resolved from 20.20.2)
  -> status=0
  VP_NODE_VERSION=20.20.2
$ vp env use --help >/dev/null
  -> status=0
  VP_NODE_VERSION=20.20.2 (expected: unchanged)
$ vp -C . env use 22.23.4 --no-install
Using Node.js v22.23.4 (resolved from 22.23.4)
  -> status=0
  VP_NODE_VERSION=22.23.4
$ complete -C 'vpr '
  build      vite build
  test:e2e   playwright test
  test:unit  vitest run
$ complete -C 'vpr test\:u'
  test:unit  vitest run
$ count a b c
  0