cmp stdout want

-- want --
{
	"ImportPath": "m/c",
	"DepsErrors": [
		{
			"ImportStack": [
				"m/a",
				"m/b",
				"m/c",
				"m/a"
			],
			"Pos": "",
			"Err": "import cycle not allowed"
		}
	]
}
{
	"ImportPath": "m/b",
	"DepsErrors": [
		{
			"ImportStack": [
				"m/a",
				"m/b",
				"m/c",
				"m/a"
			],
			"Pos": "",