versionCheckHook: Check for --version first

[jpds]

More likely to find the version number in --version than --help so look for that first.

Things done

• Built on platform:
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS tests in nixos/tests.
  • Package tests at passthru.tests.
  • Tests in lib/tests or pkgs/test for functions and "core" functionality.
• Ran nixpkgs-review on this PR. See nixpkgs-review usage.
• Tested basic functionality of all binary files, usually in ./result/bin/.
• Nixpkgs Release Notes
  • Package update: when the change is major or breaking.
• NixOS Release Notes
  • Module addition: when adding a new NixOS module.
  • Module update: when the change is significant.
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other READMEs.

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Add a 👍 reaction to pull requests you find important.

[Zaczero]

My first thought: Does this change improve anything realistically?

More likely

Is there any evidence? 👀

[jpds]

Is there any evidence? 👀

Yeah, a quick grep shows that a 800+ packages where a bunch of us decided to manually specify this over 5 who hardcoded --help.

[Zaczero]

Hmm. If "--help" is the first default, there's no reason for people to specify "--help" explicitly. I don't think your statistic is sound.

[jpds]

I know, I do not know why those people decided to specify that.

I do know that I've been adding it to my packages as I don't see the point in calling something every time when one knows it's going to fail, both at a test build level and in Hydra.

Edit: and there's also established software like ClickHouse that don't show a version number in their help usage, see: https://hydra.nixos.org/build/312909059/nixlog/2

[Zaczero]

I went ahead and run research AI agents:

Gemini:

The Dominant Pattern: The GNU style of --version (exclusively for metadata) and --help (exclusively for instruction) is the overwhelming norm.

The Modern Shift: A "Hybrid" pattern is emerging, primarily in Rust-based tooling, where version info is displayed in both locations. This accounts for roughly 15-20% of newer tools but does not displace the dedicated version flag.

Gemini 2:

Based on the analysis of 108 common Linux tools, the findings are as follows:

Approximately 93% of the analyzed tools provide their version number when the --version flag (or an equivalent such as -V or -v) is used.

Approximately 53% of these tools also include their version number within the output of the --help flag (or display it when the command is invoked with invalid options or by default).

ChatGPT:

Percentage statistics: Out of our sample of 24 tools, about 25% (roughly one-quarter) included their version number in the --help output. These were mainly interactive or user-facing tools like Bash, Wget, Apt, Vim, and Nano. In contrast, almost all tools (around 95% of those sampled) provided a dedicated --version flag (or equivalent -V) to display the version info. Only very few exceptions (≈5%) lacked a version flag (for example, the minimalist shell dash).

Based on that, I am convinced this is a positive change.

[doronbehar]

Could you please fix the staging rebase?

All good now, thank you!

[doronbehar]

Hmm maybe we should remove the versionCheckProgramArg = "--version"; lines now? We are targeting staging anyway so we can live with the large amount of rebuilds. This script can be used:

git grep -l 'versionCheckProgramArg = "--version";' | while read f; do
  sed -i '/versionCheckProgramArg/d' "$f"
done

[doronbehar]

git grep -l -e 'versionCheckProgramArg = "--version";' -e 'versionCheckProgramArg = \[ "--version" \];' | while read f; do
  sed -i '/versionCheckProgramArg/d' "$f"
  sed -i '/^$/N;/\n$/D' "$f"
done

Why didn't you use the full pattern in the sed commands? Also it seems like the last sed command removes any empty line from these files.

[jpds]

@doronbehar The last sed removes double empty lines from the files as was the case when versionCheckProgramArg was floating by itself - you can look at ahoy for example in the diff.

The pattern I just took from your command.

[doronbehar]

Ah OK I get it now , and yes indeed I used a simpler pattern match in the sed command :).

[doronbehar]

This looks good to me, but TBH I'm not sconfident enough to merge such tree wide changes . I hope we can get a few more eyes on this.

[philiptaron]

I read the whole thing. LGTM.

[philiptaron]

Here is the key change.

[doronbehar]

Tnx!

…

On 26 November 2025 18:26:12 GMT+02:00, Philip Taron ***@***.***> wrote: Merged #463218 into staging. -- Reply to this email directly or view it on GitHub: #463218 (comment) You are receiving this because you were mentioned. Message ID: ***@***.***>