How to make 'version' subcommand call 'root --version'

[eine]

I am trying to add a version subcommand to rootCmd which will produce the same result as executing root --version.

The following code is properly compiled but it produces a runtime error:

package cmd
import "github.com/spf13/cobra"

var versionCmd = &cobra.Command{
	Use:   "version",
	Short: "Print the version number of Hugo",
	Long:  `All software has versions. This is Hugo's`,
	Run: func(cmd *cobra.Command, args []string) {
		rootCmd.Run(cmd, []string{"--version"})
	},
}

func init() {
	rootCmd.AddCommand(versionCmd)
}

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x78ab9e]

So I looked in the sources of cobra and came up with:

package cmd

import (
	"text/template"
	"github.com/spf13/cobra"
)

var versionCmd = &cobra.Command{
	Use:   "version",
	Short: "Print the version number of Hugo",
	Long:  `All software has versions. This is Hugo's`,
	Run: func(cmd *cobra.Command, args []string) {
		t := template.New("version")
		template.Must(t.Parse(rootCmd.VersionTemplate()))
		err := t.Execute(rootCmd.OutOrStdout(), rootCmd)
		if err != nil {
			rootCmd.Println(err)
		}
	},
}

func init() {
	rootCmd.AddCommand(versionCmd)
}

This produces the desired result: root version and root --version produce the same output. However, I find the requirement to replicate the snippet strange.

Can anyone help me find the correct single instruction that allows to execute the root 'recursively'?

[github-actions]

This issue is being marked as stale due to a long period of inactivity

[eine]

This is still relevant.

[marckhouzam]

@eine This works for me in a small test program:

var version = &cobra.Command{
	Use:   "version",
	Short: "the version",
	Run: func(cmd *cobra.Command, args []string) {
		root := cmd.Root()
		root.SetArgs([]string{"--version"})
		root.Execute()
	},
}

[johnSchnake]

Asked and answered. Closing.