[Go] type mismatch building record with fixed-length non-nullable array

[wkalt]

Describe the usage question you have. Please include as many useful details as possible.

Hello,
Thanks for the library. I'm wondering what is wrong with the code below. I am struggling to build a record that includes a non-nullable fixed-size list.

If I change the call to FixedSizeListOfNonNullable to ListOfNonNullable my panic goes away, so being fixed-size seems relevant.

I'm not sure if this is a usage error or a bug, I'm just getting started with arrow.

func TestExample(t *testing.T) {
	pool := memory.NewGoAllocator()

	schema := arrow.NewSchema([]arrow.Field{
		{Name: "data", Type: arrow.FixedSizeListOfNonNullable(1, arrow.PrimitiveTypes.Int32)},
	}, nil)

	builder := array.NewRecordBuilder(pool, schema)

	lb := builder.Field(0).(*array.FixedSizeListBuilder)

	// append data to the value builder
	vb := lb.ValueBuilder().(*array.Int32Builder)
	vb.Append(10)

	// why is the array that comes out of here nullable?
	//_ = lb.NewArray()

	// panic here
	_ = builder.NewRecord()
	// row/array: column "data" type mismatch: got=struct<foo: fixed_size_list<item: int32, nullable>[1]>, want=struct<foo: fixed_size_list<item: int32>[1]> [recovered]
}

Component(s)

Go

[wkalt]

It seems to me that any nullability context is getting dropped for fixed-length arrays here:

https://github.com/apache/arrow/blob/main/go/arrow/array/builder.go#L358,L360

Regular lists don't have this problem because they pass the entire field structure down to the list builder constructor. Fixed size arrays need the same "WithField" treatment introduced in 8bff490ce37f0bb427ad865fae6c1d29c18d9fa7.