mergo WithSliceDeepCopy into differen types will causes painc

[zhiyu0729]

playground

package main

import (
	"testing"

	"github.com/imdario/mergo"
)

func TestMerge(t *testing.T) {
	dst := []interface{}{
		map[string]int{
			"a": 1,
		},
	}
	src := []interface{}{
		"nil",
	}

	err := mergo.Merge(&dst, src, mergo.WithSliceDeepCopy)
	if err != nil {
		t.Errorf("unexpected error %v", err)
	}
}

below is painc message

=== RUN   TestMerge
--- FAIL: TestMerge (0.00s)
panic: reflect: reflect.Value.Set using unaddressable value [recovered]
	panic: reflect: reflect.Value.Set using unaddressable value

goroutine 18 [running]:
testing.tRunner.func1.2({0x4c90a0, 0xc00009e450})
	/usr/local/go-faketime/src/testing/testing.go:1396 +0x24e
testing.tRunner.func1()
	/usr/local/go-faketime/src/testing/testing.go:1399 +0x39f
panic({0x4c90a0, 0xc00009e450})
	/usr/local/go-faketime/src/runtime/panic.go:884 +0x212
reflect.flag.mustBeAssignableSlow(0x0?)
	/usr/local/go-faketime/src/reflect/value.go:260 +0x85
reflect.flag.mustBeAssignable(...)
	/usr/local/go-faketime/src/reflect/value.go:247
reflect.Value.Set({0x4cc9c0?, 0xc0000a02d0?, 0x0?}, {0x4c90a0?, 0x50a108?, 0x0?})
	/usr/local/go-faketime/src/reflect/value.go:2154 +0x6a
github.com/imdario/mergo.deepMerge({0x4cc9c0?, 0xc0000a02d0?, 0xcc000b287f8?}, {0x4c90a0?, 0x50a108?, 0x0?}, 0x0?, 0x1, 0xc0000b2020)
	/tmp/gopath3385435001/pkg/mod/github.com/imdario/mergo@v0.3.13/merge.go:114 +0x537
github.com/imdario/mergo.deepMerge({0x4c74e0?, 0xc0000a8078?, 0x197?}, {0x4c74e0?, 0xc0000a8090?, 0x97?}, 0xc00009be30?, 0x0, 0xc0000b2020)
	/tmp/gopath3385435001/pkg/mod/github.com/imdario/mergo@v0.3.13/merge.go:230 +0x1525
github.com/imdario/mergo.merge({0x4c4de0, 0xc0000a8078}, {0x4c74e0, 0xc0000a8090}, {0xc00003c740, 0x1, 0x4b5225?})
	/tmp/gopath3385435001/pkg/mod/github.com/imdario/mergo@v0.3.13/merge.go:366 +0x32b
github.com/imdario/mergo.Merge(...)
	/tmp/gopath3385435001/pkg/mod/github.com/imdario/mergo@v0.3.13/merge.go:296
main.TestMerge(0xc000082820)
	/tmp/sandbox1600088922/prog.go:19 +0x126
testing.tRunner(0xc000082820, 0x4eb5a8)
	/usr/local/go-faketime/src/testing/testing.go:1446 +0x10b
created by testing.(*T).Run
	/usr/local/go-faketime/src/testing/testing.go:1493 +0x35f

Program exited.