json-unmarshal-panic

unexpected fault address 0x7f667c0dd45a 
fatal error: fault 
[signal SIGSEGV: segmentation violation code=0x1 addr=0x7f667c0dd45a pc=0x46a94b] 
goroutine 134 [running]: 
runtime.throw(0x19749f9, 0x5) 
	/usr/local/go/src/runtime/panic.go:566 +0x95 fp=0xc4200349d0 sp=0xc4200349b0 
runtime.sigpanic() 
	/usr/local/go/src/runtime/sigpanic_unix.go:27 +0x288 fp=0xc420034a28 sp=0xc4200349d0 
runtime.memeqbody() 
	/usr/local/go/src/runtime/asm_amd64.s:1462 +0x11b fp=0xc420034a30 sp=0xc420034a28 
encoding/json.(*decodeState).object(0xc420167860, 0x166b300, 0xc420443d40, 0x16) 
	/usr/local/go/src/encoding/json/decode.go:654 +0x1274 fp=0xc420034cc0 sp=0xc420034a30 
encoding/json.(*decodeState).value(0xc420167860, 0x166b300, 0xc420443d40, 0x16) 
	/usr/local/go/src/encoding/json/decode.go:368 +0x2cc fp=0xc420034d40 sp=0xc420034cc0 
encoding/json.(*decodeState).unmarshal(0xc420167860, 0x166b300, 0xc420443d40, 0x0, 0x0) 
	/usr/local/go/src/encoding/json/decode.go:169 +0x1fa fp=0xc420034db8 sp=0xc420034d40 
encoding/json.Unmarshal(0x7f667c0dd458, 0x68, 0x68, 0x166b300, 0xc420443d40, 0x0, 0x0) 
	/usr/local/go/src/encoding/json/decode.go:97 +0x102 fp=0xc420034e00 sp=0xc420034db8 
github.com/docker/docker/volume/store.(*VolumeStore).restore.func2(0xc4203eb7b0, 0xc42047c720, 0xc42038e6e0, 0xc42046d530) 
	/go/src/github.com/docker/docker/volume/store/restore.go:35 +0x995 fp=0xc420034f90 sp=0xc420034e00 
runtime.goexit() 
	/usr/local/go/src/runtime/asm_amd64.s:2086 +0x1 fp=0xc420034f98 sp=0xc420034f90 
created by github.com/docker/docker/volume/store.(*VolumeStore).restore 
	/go/src/github.com/docker/docker/volume/store/restore.go:78 +0x16b