fatal error: too many address space collisions for -race mode

runtime stack:
runtime.throw({0x52f342?, 0x0?})
	GOROOT/src/runtime/panic.go:1047 +0x5d fp=0x7f9a8dffb068 sp=0x7f9a8dffb038 pc=0x123e03d
runtime.(*mheap).sysAlloc(0x2a13040, 0xc3ffffffff?, 0x2a231d8, 0x1)
	GOROOT/src/runtime/malloc.go:654 +0x645 fp=0x7f9a8dffb0f8 sp=0x7f9a8dffb068 pc=0x1213b65
runtime.(*mheap).grow(0x2a13040, 0x400001?)
	GOROOT/src/runtime/mheap.go:1472 +0x7f fp=0x7f9a8dffb170 sp=0x7f9a8dffb0f8 pc=0x122f0df
runtime.(*mheap).allocSpan(0x2a13040, 0x400001, 0x0, 0xd5?)
	GOROOT/src/runtime/mheap.go:1243 +0x1b7 fp=0x7f9a8dffb208 sp=0x7f9a8dffb170 pc=0x122e9f7
runtime.(*mheap).alloc.func1()
	GOROOT/src/runtime/mheap.go:961 +0x65 fp=0x7f9a8dffb250 sp=0x7f9a8dffb208 pc=0x122e4a5
runtime.systemstack()
	src/runtime/asm_amd64.s:496 +0x49 fp=0x7f9a8dffb258 sp=0x7f9a8dffb250 pc=0x12749c9