Panic with yq with go.yaml.in/yaml/v3

[ccoVeille]

It appears that yaml.v3 is causing some panics:

goroutine 26994 [running]:
runtime/debug.Stack()
	/usr/local/go/src/runtime/panic.go:783 +0x132
go.yaml.in/yaml/v3.handleErr(0xc000bdc488)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/yaml.go:301 +0x68
panic({0x10430a0?, 0xc001931e30?})
	/usr/local/go/src/runtime/panic.go:783 +0x132
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:166 +0x174
go.yaml.in/yaml/v3.(*parser).parseChild(...)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:197
go.yaml.in/yaml/v3.(*parser).mapping(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:288 +0x22f
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:155 +0xe9
go.yaml.in/yaml/v3.(*parser).parseChild(...)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:197
go.yaml.in/yaml/v3.(*parser).mapping(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:288 +0x22f
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:155 +0xe9
go.yaml.in/yaml/v3.(*parser).parseChild(...)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:197
go.yaml.in/yaml/v3.(*parser).mapping(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:288 +0x22f
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:155 +0xe9
go.yaml.in/yaml/v3.(*parser).parseChild(...)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:197
go.yaml.in/yaml/v3.(*parser).sequence(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:262 +0x138
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:157 +0xd5
go.yaml.in/yaml/v3.(*parser).parseChild(...)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:197
go.yaml.in/yaml/v3.(*parser).mapping(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:288 +0x22f
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:155 +0xe9
go.yaml.in/yaml/v3.(*parser).parseChild(...)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:197
go.yaml.in/yaml/v3.(*parser).mapping(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:288 +0x22f
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:155 +0xe9
go.yaml.in/yaml/v3.(*parser).parseChild(...)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:197
go.yaml.in/yaml/v3.(*parser).document(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:206 +0x79
go.yaml.in/yaml/v3.(*parser).parse(0xc0003aac08)
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/decode.go:159 +0xa5
go.yaml.in/yaml/v3.(*Decoder).Decode(0xc0002d1570, {0x11c5860, 0xc000bc0e60})
	/go/pkg/mod/go.yaml.in/yaml/v3@v3.0.4/yaml.go:121 +0x10c
github.com/mikefarah/yq/v4/pkg/yqlib.(*yamlDecoder).Decode(0xc0002d1570)
	/go/pkg/mod/github.com/mikefarah/yq/v4@v4.47.3-0.20250910084752-4532346e136f/pkg/yqlib/decoder_yaml.go:115 +0x46
github.com/mikefarah/yq/v4/pkg/yqlib.(*streamEvaluator).Evaluate(0xc000bdc688, {0x0, 0x0}, {0x14598a0?, 0xc000529500?}, 0xc001008c80, {0x1465b70, 0xc000823420}, {0x1461390, 0xc0002d1570})
	/go/pkg/mod/github.com/mikefarah/yq/v4@v4.47.3-0.20250910084752-4532346e136f/pkg/yqlib/stream_evaluator.go:86 +0xb3
github.com/mikefarah/yq/v4/pkg/yqlib.(*stringEvaluator).Evaluate(0x12e6c43?, {0xc0004705c0, 0x3a}, {0xc001906000, 0x123fe}, {0x1465ba8, 0xc00023fe30}, {0x1461390, 0xc0002d1570})
	/go/pkg/mod/github.com/mikefarah/yq/v4@v4.47.3-0.20250910084752-4532346e136f/pkg/yqlib/string_evaluator.go:62 +0x451

Originally posted by @n471d in #2468 (comment)

[ccoVeille]

@n471d

I checked go.yaml.in/yaml/v3@3.0.4

And apparently the panic comes from here

https://github.com/yaml/go-yaml/blob/c3552c15f996075a7634df5159d9161c67bf3d76/decode.go#L166

  panic("internal error: attempted to parse unknown event (please report): " + p.event.typ.String())

I assume the panic is not caught by yq otherwise we wouldn't have this error stack

So could you communicate me the error message you got with the panic ?

It could help to understand what type had the event, and thus try to find a solution.

[ccoVeille]

@ingydotnet here is the PR I talked you about earlier