goversion: print your Go binary's version on -help

Simply add the following to your usage function:

import "runtime/debug"
...

if bi, ok := debug.ReadBuildInfo(); ok { // on success
  fmt.Fprintf(flag.CommandLine.Output(), "Version: %s\n\n", bi.Main.Version)
}

It then looks like this:

$ go run github.com/ypsu/pkgtrim@latest -help 2>&1 | grep Version
Version: v0.260813.0

That v0.260813.0 label is the git tag from which the binary was built. Bonus points if your release git tags are date-based because then I can tell how old the binary is (see @/yseq). For local dev builds it will say (devel).

For reference, you can check the version for any Go binary like this:

$ go install github.com/ypsu/pkgtrim@latest
$ go version -m "$HOME/go/bin/pkgtrim" | grep ^\\s*mod
	mod	github.com/ypsu/pkgtrim	v0.260813.0	h1:AUKnZ5RJTLqYTOUQd1B8Ap0Mlm9wBTJSf/ZLjgXh9vM=

Unfortunately, at the time of writing, this won't work for most packages built by Linux distributions (e.g. go version -m /usr/bin/fzf) because they are building Go binaries weirdly. C'est la vie. Nevertheless, I think it's still a useful addition right in -help, and maybe it inspires packagers to figure out the build process.

You can read more about this at https://go.dev/doc/go1.18#go-version and https://antonz.org/go-1-24/#main-modules-version.

Published on 2026-09-07.

Add new comment:

(Adding a new comment or reply requires javascript.)

to the frontpage