Error while merging anchors

[AbrahamTewa]

Hi !

I have an error when I try to unmarshall YAML with merging anchors:

package main

import (
	"log"

	yaml "gopkg.in/yaml.v3"
)

var data = `
anchorA: &anchorA
  A: 1

  anchorB: &anchorB
  B: 2

testFinal:
  <<: *anchorA
  <<: *anchorB
`

func main() {
	m := make(map[interface{}]interface{})

	err := yaml.Unmarshal([]byte(data), &m)
	log.Fatalf("error: %v", err)
}

I get an error:

error: yaml: unmarshal errors:
  line 10: mapping key "<<" already defined at line 9

[perlpunk]

try this:

testFinal:
  <<: [*anchorA, *anchorB]

[AbrahamTewa]

This syntax seems to work (no errors).

[AbrahamTewa]

Hi !
Any update on this issue ?

Thanks !

[perlpunk]

I wouldn't expect an update. My suggestion is the official way to merge multiple anchors, see https://yaml.org/type/merge.html

go-yaml's behaviour is not a bug. You better rewrite your YAML.