packer boot panic

panic.log

 ==> virtualbox: Waiting 4s for boot...
 ==> virtualbox: Typing the boot command...
 panic: EOF

 goroutine 50 [running]:
 log.Panic(0x7f296424bfa0, 0x1, 0x1)
    /Users/mitchellh/go/src/pkg/log/log.go:307 +0xaa
 github.com/mitchellh/packer/packer/rpc.func·001()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/builder.go:73 +0x23e
 created by github.com/mitchellh/packer/packer/rpc.(*builder).Run
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/builder.go:77 +0x1b0

 goroutine 1 [chan receive]:
 net/rpc.(*Client).Call(0xc2000d2e40, 0x6cd0b0, 0xb, 0x5ea4a0, 0xc20012a330, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:310 +0xa4
 github.com/mitchellh/packer/packer/rpc.(*command).Run(0xc200000650, 0xc2000d25a0, 0xc2000d2540, 0xc200097020, 0x3, ...)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/command.go:46 +0x154
 github.com/mitchellh/packer/packer/plugin.(*cmdCommand).Run(0xc200105880, 0xc2000d25a0, 0xc2000d2540, 0xc200097020, 0x3, ...)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/command.go:29 +0xc2
 github.com/mitchellh/packer/packer.(*coreEnvironment).Cli(0xc2000d2540, 0xc200097010, 0x4, 0x4, 0x0, ...)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/environment.go:262 +0x85d
 main.main()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer.go:109 +0x127c

 goroutine 3 [syscall]:
 os/signal.loop()
    /Users/mitchellh/go/src/pkg/os/signal/signal_unix.go:21 +0x1c
 created by os/signal.init·1
    /Users/mitchellh/go/src/pkg/os/signal/signal_unix.go:27 +0x2f

 goroutine 5 [syscall]:
 syscall.Syscall()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:16 +0x5
 syscall.read(0x0, 0xc200114000, 0x8000, 0x8000, 0x3c000fa630, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:2337 +0x70
 syscall.Read(0x0, 0xc200114000, 0x8000, 0x8000, 0x1000fa630, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_unix.go:132 +0x5a
 os.(*File).read(0xc200000000, 0xc200114000, 0x8000, 0x8000, 0x41e29a, ...)
    /Users/mitchellh/go/src/pkg/os/file_unix.go:174 +0x60
 os.(*File).Read(0xc200000000, 0xc200114000, 0x8000, 0x8000, 0x8000, ...)
    /Users/mitchellh/go/src/pkg/os/file.go:95 +0x96
 io.Copy(0xc2000b41b0, 0xc200000388, 0xc2000b42d0, 0xc200000000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:348 +0x1c6
 main.func·002()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/stdin.go:23 +0x94
 created by main.setupStdin
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/stdin.go:24 +0xaf

 goroutine 6 [chan receive]:
 main.func·003()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/stdin.go:34 +0x88
 created by main.setupStdin
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/stdin.go:36 +0x18c

 goroutine 7 [chan receive]:
 main.func·001()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/signal.go:20 +0x46
 created by main.setupSignalHandlers
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/signal.go:32 +0x115

 goroutine 8 [syscall]:
 syscall.Syscall()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:16 +0x5
 syscall.read(0x5, 0xc200171010, 0x5f0, 0x5f0, 0x10, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:2337 +0x70
 syscall.Read(0x5, 0xc200171010, 0x5f0, 0x5f0, 0x416f24, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_unix.go:132 +0x5a
 os.(*File).read(0xc200000558, 0xc200171010, 0x5f0, 0x5f0, 0xc200171000, ...)
    /Users/mitchellh/go/src/pkg/os/file_unix.go:174 +0x60
 os.(*File).Read(0xc200000558, 0xc200171010, 0x5f0, 0x5f0, 0x10, ...)
    /Users/mitchellh/go/src/pkg/os/file.go:95 +0x96
 bytes.(*Buffer).ReadFrom(0xc2000c3380, 0xc2000b42d0, 0xc200000558, 0x10, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bytes/buffer.go:169 +0x203
 io.Copy(0xc20012a000, 0xc2000c3380, 0xc2000b42d0, 0xc200000558, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:340 +0xa3
 os/exec.func·003(0x0, 0x7f296453e160)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:207 +0x60
 os/exec.func·004(0xc2001053a0)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:276 +0x2a
 created by os/exec.(*Cmd).Start
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:277 +0x732

 goroutine 9 [syscall]:
 syscall.Syscall()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:16 +0x5
 syscall.read(0x7, 0xc20013e000, 0x8000, 0x8000, 0xc20011c400, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:2337 +0x70
 syscall.Read(0x7, 0xc20013e000, 0x8000, 0x8000, 0x7303b0, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_unix.go:132 +0x5a
 os.(*File).read(0xc200000580, 0xc20013e000, 0x8000, 0x8000, 0xc20013e000, ...)
    /Users/mitchellh/go/src/pkg/os/file_unix.go:174 +0x60
 os.(*File).Read(0xc200000580, 0xc20013e000, 0x8000, 0x8000, 0x30, ...)
    /Users/mitchellh/go/src/pkg/os/file.go:95 +0x96
 io.Copy(0xc2000fafc0, 0xc200000520, 0xc2000b42d0, 0xc200000580, 0x2aa, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:348 +0x1c6
 os/exec.func·003(0xc2000b5680, 0x5fb660)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:207 +0x60
 os/exec.func·004(0xc200105400)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:276 +0x2a
 created by os/exec.(*Cmd).Start
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:277 +0x732

 goroutine 10 [syscall]:
 syscall.Syscall6()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:41 +0x5
 syscall.wait4(0x3e0a, 0xc2000005c0, 0x0, 0xc2000c6360, 0x100000001, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:1640 +0x7b
 syscall.Wait4(0x3e0a, 0x7f2964506e44, 0x0, 0xc2000c6360, 0xc1fffecef8, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_linux.go:222 +0x6c
 os.(*Process).wait(0xc200105660, 0xc200131000, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/os/exec_unix.go:22 +0xea
 os.(*Process).Wait(0xc200105660, 0x2300000000, 0x421a5e, 0x800)
    /Users/mitchellh/go/src/pkg/os/doc.go:43 +0x25
 os/exec.(*Cmd).Wait(0xc2000cb140, 0x100000000, 0x40f0a9)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:310 +0x197
 github.com/mitchellh/packer/packer/plugin.func·006()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:253 +0x60
 created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:261 +0x7c5

 goroutine 11 [semacquire]:
 sync.runtime_Semacquire(0xc2002e0270)
    /Users/mitchellh/go/src/pkg/runtime/zsema_linux_amd64.c:165 +0x2e
 sync.(*Cond).Wait(0xc200125270)
    /Users/mitchellh/go/src/pkg/sync/cond.go:74 +0x95
 io.(*pipe).read(0xc200125240, 0xc20015f000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/pipe.go:52 +0x1f2
 io.(*PipeReader).Read(0xc200000518, 0xc20015f000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/pipe.go:130 +0x5d
 bufio.(*Reader).fill(0xc2000d27e0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).ReadSlice(0xc2000d27e0, 0xc20012800a, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:262 +0x202
 bufio.(*Reader).ReadBytes(0xc2000d27e0, 0xa, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:343 +0xb7
 bufio.(*Reader).ReadString(0xc2000d27e0, 0xa, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:383 +0x53
 github.com/mitchellh/packer/packer/plugin.(*Client).logStderr(0xc2000faf60, 0xc20012a270, 0xc200000518)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:308 +0x60
 created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:264 +0x80b

 goroutine 13 [IO wait]:
 net.runtime_pollWait(0x7f296428cf00, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc200173080, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200173000, 0xc200176000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc200000640, 0xc200176000, 0x1000, 0x1000, 0x17d, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc2000d2de0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc2000d2de0, 0xc2001274c0, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc2000d2de0, 0xc2001274c0, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc2000d2de0, 0xc2001274c0, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc2000d2de0, 0xc2001274c0, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc200175000, 0x0)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc200175000, 0xc20012a200, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc200175000, 0x5eb620, 0xc20012a2a0, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc200175000, 0x5eb620, 0xc20012a2a0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobClientCodec).ReadResponseHeader(0xc200178000, 0xc20012a2a0, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:218 +0x3d
 net/rpc.(*Client).input(0xc2000d2e40)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:106 +0xba
 created by net/rpc.NewClientWithCodec
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:196 +0x8f

 goroutine 14 [IO wait]:
 net.runtime_pollWait(0x7f296428cdc0, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc2000c6500, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc2000c6480, 0xc2001a2000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2000009a8, 0xc2001a2000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc2000d28a0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc2000d28a0, 0xc2000b3c90, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc2000d28a0, 0xc2000b3c90, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc2000d28a0, 0xc2000b3c90, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc2000d28a0, 0xc2000b3c90, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc2001a1000, 0xc2001a103c)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc2001a1000, 0xc2000c5f00, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc2001a1000, 0x5eb5e0, 0xc2000c5f20, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc2001a1000, 0x5eb5e0, 0xc2000c5f20, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobServerCodec).ReadRequestHeader(0xc2000b4270, 0xc2000c5f20, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:398 +0x3d
 net/rpc.(*Server).readRequestHeader(0xc2000f9c40, 0xc2000c71c0, 0xc2000b4270, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:549 +0x99
 net/rpc.(*Server).readRequest(0xc2000f9c40, 0xc2000c71c0, 0xc2000b4270, 0xc20017a080, 0xc200105d60, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:516 +0x9e
 net/rpc.(*Server).ServeCodec(0xc2000f9c40, 0xc2000c71c0, 0xc2000b4270)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:435 +0x64
 net/rpc.(*Server).ServeConn(0xc2000f9c40, 0xc2000f9980, 0xc2000009a8)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:427 +0x13e
 github.com/mitchellh/packer/packer/rpc.func·005()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:84 +0xf7
 created by github.com/mitchellh/packer/packer/rpc.serveSingleConn
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:85 +0xb8

 goroutine 21 [IO wait]:
 net.runtime_pollWait(0x7f296428cbe0, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc2001d2230, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc2001d21b0, 0xc2001dd000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc200000f70, 0xc2001dd000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc2001a8cc0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc2001a8cc0, 0xc200127810, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc2001a8cc0, 0xc200127810, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc2001a8cc0, 0xc200127810, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc2001a8cc0, 0xc200127810, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc2001d40f0, 0xc2002ab800)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc2001d40f0, 0xc2001ad700, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc2001d40f0, 0x5eb5e0, 0xc2001ad740, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc2001d40f0, 0x5eb5e0, 0xc2001ad740, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobServerCodec).ReadRequestHeader(0xc200178d50, 0xc2001ad740, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:398 +0x3d
 net/rpc.(*Server).readRequestHeader(0xc2001a6a40, 0xc2000c71c0, 0xc200178d50, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:549 +0x99
 net/rpc.(*Server).readRequest(0xc2001a6a40, 0xc2000c71c0, 0xc200178d50, 0xc2001d7100, 0xc2002b61c0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:516 +0x9e
 net/rpc.(*Server).ServeCodec(0xc2001a6a40, 0xc2000c71c0, 0xc200178d50)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:435 +0x64
 net/rpc.(*Server).ServeConn(0xc2001a6a40, 0xc2000f9980, 0xc200000f70)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:427 +0x13e
 github.com/mitchellh/packer/packer/rpc.func·005()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:84 +0xf7
 created by github.com/mitchellh/packer/packer/rpc.serveSingleConn
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:85 +0xb8

 goroutine 23 [syscall]:
 syscall.Syscall()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:16 +0x5
 syscall.read(0x10, 0xc200122010, 0x5f0, 0x5f0, 0x10, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:2337 +0x70
 syscall.Read(0x10, 0xc200122010, 0x5f0, 0x5f0, 0x416f24, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_unix.go:132 +0x5a
 os.(*File).read(0xc200000ff0, 0xc200122010, 0x5f0, 0x5f0, 0xc200122000, ...)
    /Users/mitchellh/go/src/pkg/os/file_unix.go:174 +0x60
 os.(*File).Read(0xc200000ff0, 0xc200122010, 0x5f0, 0x5f0, 0x10, ...)
    /Users/mitchellh/go/src/pkg/os/file.go:95 +0x96
 bytes.(*Buffer).ReadFrom(0xc2001da1c0, 0xc2000b42d0, 0xc200000ff0, 0x10, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bytes/buffer.go:169 +0x203
 io.Copy(0xc20012a000, 0xc2001da1c0, 0xc2000b42d0, 0xc200000ff0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:340 +0xa3
 os/exec.func·003(0x426520, 0x5ef160)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:207 +0x60
 os/exec.func·004(0xc2001ad820)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:276 +0x2a
 created by os/exec.(*Cmd).Start
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:277 +0x732

 goroutine 24 [syscall]:
 syscall.Syscall()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:16 +0x5
 syscall.read(0x12, 0xc2001fa000, 0x8000, 0x8000, 0xc200165b00, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:2337 +0x70
 syscall.Read(0x12, 0xc2001fa000, 0x8000, 0x8000, 0x7303b0, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_unix.go:132 +0x5a
 os.(*File).read(0xc2001e5018, 0xc2001fa000, 0x8000, 0x8000, 0xc2001fa000, ...)
    /Users/mitchellh/go/src/pkg/os/file_unix.go:174 +0x60
 os.(*File).Read(0xc2001e5018, 0xc2001fa000, 0x8000, 0x8000, 0x33, ...)
    /Users/mitchellh/go/src/pkg/os/file.go:95 +0x96
 io.Copy(0xc2000fafc0, 0xc200000fb8, 0xc2000b42d0, 0xc2001e5018, 0x135, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:348 +0x1c6
 os/exec.func·003(0xc2000b5680, 0x5fb660)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:207 +0x60
 os/exec.func·004(0xc2001ad880)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:276 +0x2a
 created by os/exec.(*Cmd).Start
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:277 +0x732

 goroutine 25 [syscall]:
 syscall.Syscall6()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:41 +0x5
 syscall.wait4(0x3e1d, 0xc2001e5100, 0x0, 0xc200203000, 0x100000001, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:1640 +0x7b
 syscall.Wait4(0x3e1d, 0x7f2964299e44, 0x0, 0xc200203000, 0xc1fffdfdf8, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_linux.go:222 +0x6c
 os.(*Process).wait(0xc2001adae0, 0xc200202000, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/os/exec_unix.go:22 +0xea
 os.(*Process).Wait(0xc2001adae0, 0x2300000000, 0x421a5e, 0x800)
    /Users/mitchellh/go/src/pkg/os/doc.go:43 +0x25
 os/exec.(*Cmd).Wait(0xc2001df000, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:310 +0x197
 github.com/mitchellh/packer/packer/plugin.func·006()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:253 +0x60
 created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:261 +0x7c5

 goroutine 26 [semacquire]:
 sync.runtime_Semacquire(0xc2001e5228)
    /Users/mitchellh/go/src/pkg/runtime/zsema_linux_amd64.c:165 +0x2e
 sync.(*Cond).Wait(0xc2001d6270)
    /Users/mitchellh/go/src/pkg/sync/cond.go:74 +0x95
 io.(*pipe).read(0xc2001d6240, 0xc20021f000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/pipe.go:52 +0x1f2
 io.(*PipeReader).Read(0xc200000fb0, 0xc20021f000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/pipe.go:130 +0x5d
 bufio.(*Reader).fill(0xc20021e000)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).ReadSlice(0xc20021e000, 0xc20012800a, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:262 +0x202
 bufio.(*Reader).ReadBytes(0xc20021e000, 0xa, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:343 +0xb7
 bufio.(*Reader).ReadString(0xc20021e000, 0xa, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:383 +0x53
 github.com/mitchellh/packer/packer/plugin.(*Client).logStderr(0xc200178db0, 0xc20012a270, 0xc200000fb0)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:308 +0x60
 created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:264 +0x80b

 goroutine 27 [IO wait]:
 net.runtime_pollWait(0x7f296428cb40, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc200226080, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200226000, 0xc20022a000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc200000e30, 0xc20022a000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc20021ec00)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc20021ec00, 0xc200127d20, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc20021ec00, 0xc200127d20, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc20021ec00, 0xc200127d20, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc20021ec00, 0xc200127d20, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc200229000, 0xc20022903c)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc200229000, 0xc200224600, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc200229000, 0x5eb620, 0xc200224600, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc200229000, 0x5eb620, 0xc200224600, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobClientCodec).ReadResponseHeader(0xc200178690, 0xc200224600, 0xc2002d2b10, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:218 +0x3d
 net/rpc.(*Client).input(0xc20021ec60)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:106 +0xba
 created by net/rpc.NewClientWithCodec
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:196 +0x8f

 goroutine 28 [IO wait]:
 net.runtime_pollWait(0x7f296428ca00, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc2002261a0, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200226120, 0xc200233000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2001e5408, 0xc200233000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc20021ecc0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc20021ecc0, 0xc200127e40, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc20021ecc0, 0xc200127e40, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc20021ecc0, 0xc200127e40, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc20021ecc0, 0xc200127e40, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc2002290f0, 0xc200121e00)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc2002290f0, 0xc2002d9700, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc2002290f0, 0x5eb5e0, 0xc2002d9780, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc2002290f0, 0x5eb5e0, 0xc2002d9780, 0x7f296453e000, 0xc2002d9380, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobServerCodec).ReadRequestHeader(0xc200178a50, 0xc2002d9780, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:398 +0x3d
 net/rpc.(*Server).readRequestHeader(0xc2002271c0, 0xc2000c71c0, 0xc200178a50, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:549 +0x99
 net/rpc.(*Server).readRequest(0xc2002271c0, 0xc2000c71c0, 0xc200178a50, 0xc20022d000, 0xc2001ade00, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:516 +0x9e
 net/rpc.(*Server).ServeCodec(0xc2002271c0, 0xc2000c71c0, 0xc200178a50)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:435 +0x64
 net/rpc.(*Server).ServeConn(0xc2002271c0, 0xc2000f9980, 0xc2001e5408)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:427 +0x13e
 github.com/mitchellh/packer/packer/rpc.func·005()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:84 +0xf7
 created by github.com/mitchellh/packer/packer/rpc.serveSingleConn
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:85 +0xb8

 goroutine 30 [syscall]:
 syscall.Syscall()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:16 +0x5
 syscall.read(0x15, 0xc200276010, 0x5f0, 0x5f0, 0x10, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:2337 +0x70
 syscall.Read(0x15, 0xc200276010, 0x5f0, 0x5f0, 0x416f24, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_unix.go:132 +0x5a
 os.(*File).read(0xc2001e5488, 0xc200276010, 0x5f0, 0x5f0, 0xc200276000, ...)
    /Users/mitchellh/go/src/pkg/os/file_unix.go:174 +0x60
 os.(*File).Read(0xc2001e5488, 0xc200276010, 0x5f0, 0x5f0, 0x10, ...)
    /Users/mitchellh/go/src/pkg/os/file.go:95 +0x96
 bytes.(*Buffer).ReadFrom(0xc20022fe70, 0xc2000b42d0, 0xc2001e5488, 0x10, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bytes/buffer.go:169 +0x203
 io.Copy(0xc20012a000, 0xc20022fe70, 0xc2000b42d0, 0xc2001e5488, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:340 +0xa3
 os/exec.func·003(0x426520, 0x5ef160)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:207 +0x60
 os/exec.func·004(0xc2001adee0)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:276 +0x2a
 created by os/exec.(*Cmd).Start
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:277 +0x732

 goroutine 31 [syscall]:
 syscall.Syscall()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:16 +0x5
 syscall.read(0x17, 0xc20024e000, 0x8000, 0x8000, 0xc2001f7400, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:2337 +0x70
 syscall.Read(0x17, 0xc20024e000, 0x8000, 0x8000, 0x7303b0, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_unix.go:132 +0x5a
 os.(*File).read(0xc2001e54b0, 0xc20024e000, 0x8000, 0x8000, 0xc20024e000, ...)
    /Users/mitchellh/go/src/pkg/os/file_unix.go:174 +0x60
 os.(*File).Read(0xc2001e54b0, 0xc20024e000, 0x8000, 0x8000, 0x33, ...)
    /Users/mitchellh/go/src/pkg/os/file.go:95 +0x96
 io.Copy(0xc2000fafc0, 0xc2001e5450, 0xc2000b42d0, 0xc2001e54b0, 0x132, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:348 +0x1c6
 os/exec.func·003(0xc2000b5680, 0x5fb660)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:207 +0x60
 os/exec.func·004(0xc2001adf40)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:276 +0x2a
 created by os/exec.(*Cmd).Start
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:277 +0x732

 goroutine 32 [syscall]:
 syscall.Syscall6()
    /Users/mitchellh/go/src/pkg/syscall/asm_linux_amd64.s:41 +0x5
 syscall.wait4(0x3e25, 0xc2001e54f0, 0x0, 0xc2002262d0, 0x100000001, ...)
    /Users/mitchellh/go/src/pkg/syscall/zerrors_linux_amd64.go:1640 +0x7b
 syscall.Wait4(0x3e25, 0x7f2964278e44, 0x0, 0xc2002262d0, 0xc1fffdde78, ...)
    /Users/mitchellh/go/src/pkg/syscall/syscall_linux.go:222 +0x6c
 os.(*Process).wait(0xc20023b1a0, 0xc200221800, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/os/exec_unix.go:22 +0xea
 os.(*Process).Wait(0xc20023b1a0, 0x2300000000, 0x421a5e, 0x800)
    /Users/mitchellh/go/src/pkg/os/doc.go:43 +0x25
 os/exec.(*Cmd).Wait(0xc200234000, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/os/exec/exec.go:310 +0x197
 github.com/mitchellh/packer/packer/plugin.func·006()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:253 +0x60
 created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:261 +0x7c5

 goroutine 33 [semacquire]:
 sync.runtime_Semacquire(0xc2001e5518)
    /Users/mitchellh/go/src/pkg/runtime/zsema_linux_amd64.c:165 +0x2e
 sync.(*Cond).Wait(0xc20022b270)
    /Users/mitchellh/go/src/pkg/sync/cond.go:74 +0x95
 io.(*pipe).read(0xc20022b240, 0xc200271000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/pipe.go:52 +0x1f2
 io.(*PipeReader).Read(0xc2001e5448, 0xc200271000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/io/pipe.go:130 +0x5d
 bufio.(*Reader).fill(0xc200270000)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).ReadSlice(0xc200270000, 0xc20012800a, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:262 +0x202
 bufio.(*Reader).ReadBytes(0xc200270000, 0xa, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:343 +0xb7
 bufio.(*Reader).ReadString(0xc200270000, 0xa, 0x0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:383 +0x53
 github.com/mitchellh/packer/packer/plugin.(*Client).logStderr(0xc200178b40, 0xc20012a270, 0xc2001e5448)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:308 +0x60
 created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/client.go:264 +0x80b

 goroutine 34 [IO wait]:
 net.runtime_pollWait(0x7f296428c960, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc200278080, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200278000, 0xc20027d000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2001e5720, 0xc20027d000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc20027c000)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc20027c000, 0xc20023c420, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc20027c000, 0xc20023c420, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc20027c000, 0xc20023c420, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc20027c000, 0xc20023c420, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc20027b000, 0xc20027b03c)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc20027b000, 0xc200275c00, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc20027b000, 0x5eb620, 0xc200275c00, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc20027b000, 0x5eb620, 0xc200275c00, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobClientCodec).ReadResponseHeader(0xc2002756c0, 0xc200275c00, 0xc2002c9c50, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:218 +0x3d
 net/rpc.(*Client).input(0xc20027c060)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:106 +0xba
 created by net/rpc.NewClientWithCodec
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:196 +0x8f

 goroutine 35 [IO wait]:
 net.runtime_pollWait(0x7f296428c820, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc2002781a0, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200278120, 0xc200284000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2001e5810, 0xc200284000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc20027c0c0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc20027c0c0, 0xc20023c590, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc20027c0c0, 0xc20023c590, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc20027c0c0, 0xc20023c590, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc20027c0c0, 0xc20023c590, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc20027b0f0, 0xc2000c9dc0)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc20027b0f0, 0xc2002cd700, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc20027b0f0, 0x5eb5e0, 0xc2002cd780, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc20027b0f0, 0x5eb5e0, 0xc2002cd780, 0x7f296453e000, 0xc2002cd260, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobServerCodec).ReadRequestHeader(0xc200275b40, 0xc2002cd780, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:398 +0x3d
 net/rpc.(*Server).readRequestHeader(0xc2002791c0, 0xc2000c71c0, 0xc200275b40, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:549 +0x99
 net/rpc.(*Server).readRequest(0xc2002791c0, 0xc2000c71c0, 0xc200275b40, 0xc20027f000, 0xc20023b660, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:516 +0x9e
 net/rpc.(*Server).ServeCodec(0xc2002791c0, 0xc2000c71c0, 0xc200275b40)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:435 +0x64
 net/rpc.(*Server).ServeConn(0xc2002791c0, 0xc2000f9980, 0xc2001e5810)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:427 +0x13e
 github.com/mitchellh/packer/packer/rpc.func·005()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:84 +0xf7
 created by github.com/mitchellh/packer/packer/rpc.serveSingleConn
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:85 +0xb8

 goroutine 37 [IO wait]:
 net.runtime_pollWait(0x7f296428c6e0, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc200289080, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200289000, 0xc20028c000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2001e5548, 0xc20028c000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc200270060)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc200270060, 0xc20023c620, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc200270060, 0xc20023c620, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc200270060, 0xc20023c620, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc200270060, 0xc20023c620, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc20028b000, 0xc20011f000)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc20028b000, 0xc20023bc00, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc20028b000, 0x5eb5e0, 0xc20023bc40, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc20028b000, 0x5eb5e0, 0xc20023bc40, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobServerCodec).ReadRequestHeader(0xc200275cc0, 0xc20023bc40, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:398 +0x3d
 net/rpc.(*Server).readRequestHeader(0xc200279740, 0xc2000c71c0, 0xc200275cc0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:549 +0x99
 net/rpc.(*Server).readRequest(0xc200279740, 0xc2000c71c0, 0xc200275cc0, 0xc20027f300, 0xc200290160, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:516 +0x9e
 net/rpc.(*Server).ServeCodec(0xc200279740, 0xc2000c71c0, 0xc200275cc0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:435 +0x64
 net/rpc.(*Server).ServeConn(0xc200279740, 0xc2000f9980, 0xc2001e5548)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:427 +0x13e
 github.com/mitchellh/packer/packer/rpc.func·005()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:84 +0xf7
 created by github.com/mitchellh/packer/packer/rpc.serveSingleConn
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:85 +0xb8

 goroutine 40 [IO wait]:
 net.runtime_pollWait(0x7f296428c5a0, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc2002782c0, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200278240, 0xc20029b000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2001e5940, 0xc20029b000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc20027c120)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc20027c120, 0xc20023c9b0, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc20027c120, 0xc20023c9b0, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc20027c120, 0xc20023c9b0, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc20027c120, 0xc20023c9b0, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc20027b1e0, 0xc20027b21c)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc20027b1e0, 0xc200290500, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc20027b1e0, 0x5eb5e0, 0xc2002905a0, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc20027b1e0, 0x5eb5e0, 0xc2002905a0, 0x7f2964542f10, 0xc20029d3a0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobServerCodec).ReadRequestHeader(0xc2002874b0, 0xc2002905a0, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:398 +0x3d
 net/rpc.(*Server).readRequestHeader(0xc200294140, 0xc2000c71c0, 0xc2002874b0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:549 +0x99
 net/rpc.(*Server).readRequest(0xc200294140, 0xc2000c71c0, 0xc2002874b0, 0xc200298200, 0xc20023b880, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:516 +0x9e
 net/rpc.(*Server).ServeCodec(0xc200294140, 0xc2000c71c0, 0xc2002874b0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:435 +0x64
 net/rpc.(*Server).ServeConn(0xc200294140, 0xc2000f9980, 0xc2001e5940)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:427 +0x13e
 github.com/mitchellh/packer/packer/rpc.func·005()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:84 +0xf7
 created by github.com/mitchellh/packer/packer/rpc.serveSingleConn
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:85 +0xb8

 goroutine 46 [IO wait]:
 net.runtime_pollWait(0x7f296428c460, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc2002893e0, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc200289360, 0xc2002eb000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2002e0408, 0xc2002eb000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc2002704e0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc2002704e0, 0xc2002e1220, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc2002704e0, 0xc2002e1220, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc2002704e0, 0xc2002e1220, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc2002704e0, 0xc2002e1220, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc20028b1e0, 0xc2003010e0)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc20028b1e0, 0xc2002e5200, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc20028b1e0, 0x5eb5e0, 0xc2002e5220, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc20028b1e0, 0x5eb5e0, 0xc2002e5220, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobServerCodec).ReadRequestHeader(0xc2002dd9f0, 0xc2002e5220, 0x0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:398 +0x3d
 net/rpc.(*Server).readRequestHeader(0xc2002944c0, 0xc2000c71c0, 0xc2002dd9f0, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:549 +0x99
 net/rpc.(*Server).readRequest(0xc2002944c0, 0xc2000c71c0, 0xc2002dd9f0, 0xc200298400, 0xc200300620, ...)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:516 +0x9e
 net/rpc.(*Server).ServeCodec(0xc2002944c0, 0xc2000c71c0, 0xc2002dd9f0)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:435 +0x64
 net/rpc.(*Server).ServeConn(0xc2002944c0, 0xc2000f9980, 0xc2002e0408)
    /Users/mitchellh/go/src/pkg/net/rpc/server.go:427 +0x13e
 github.com/mitchellh/packer/packer/rpc.func·005()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:84 +0xf7
 created by github.com/mitchellh/packer/packer/rpc.serveSingleConn
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/server.go:85 +0xb8

 goroutine 48 [IO wait]:
 net.runtime_pollWait(0x7f296428c3c0, 0x72, 0x0)
    /Users/mitchellh/go/src/pkg/runtime/znetpoll_linux_amd64.c:118 +0x82
 net.(*pollDesc).WaitRead(0xc200289470, 0xb, 0xc2000fa210)
    /Users/mitchellh/go/src/pkg/net/fd_poll_runtime.go:75 +0x31
 net.(*netFD).Read(0xc2002893f0, 0xc2002ed000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/fd_unix.go:195 +0x2b3
 net.(*conn).Read(0xc2002e04a0, 0xc2002ed000, 0x1000, 0x1000, 0x0, ...)
    /Users/mitchellh/go/src/pkg/net/net.go:123 +0xc3
 bufio.(*Reader).fill(0xc2002705a0)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:79 +0x10c
 bufio.(*Reader).Read(0xc2002705a0, 0xc2002e1320, 0x1, 0x9, 0x1, ...)
    /Users/mitchellh/go/src/pkg/bufio/bufio.go:147 +0x1b0
 io.ReadAtLeast(0xc20012af90, 0xc2002705a0, 0xc2002e1320, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:284 +0xf7
 io.ReadFull(0xc20012af90, 0xc2002705a0, 0xc2002e1320, 0x1, 0x9, ...)
    /Users/mitchellh/go/src/pkg/io/io.go:302 +0x6f
 encoding/gob.decodeUintReader(0xc20012af90, 0xc2002705a0, 0xc2002e1320, 0x9, 0x9, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decode.go:65 +0xaa
 encoding/gob.(*Decoder).recvMessage(0xc20028b2d0, 0xc200292600)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:73 +0x4b
 encoding/gob.(*Decoder).decodeTypeSequence(0xc20028b2d0, 0xc2000fa800, 0x160)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:159 +0x47
 encoding/gob.(*Decoder).DecodeValue(0xc20028b2d0, 0x5eb620, 0xc2000fa870, 0x160, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:223 +0x101
 encoding/gob.(*Decoder).Decode(0xc20028b2d0, 0x5eb620, 0xc2000fa870, 0x0, 0x0, ...)
    /Users/mitchellh/go/src/pkg/encoding/gob/decoder.go:202 +0x1c3
 net/rpc.(*gobClientCodec).ReadResponseHeader(0xc2002ddc60, 0xc2000fa870, 0xc2003187b0, 0x0)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:218 +0x3d
 net/rpc.(*Client).input(0xc200270600)
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:106 +0xba
 created by net/rpc.NewClientWithCodec
    /Users/mitchellh/go/src/pkg/net/rpc/client.go:196 +0x8f

 goroutine 49 [chan receive]:
 github.com/mitchellh/packer/packer/rpc.(*builder).Run(0xc200000738, 0xc2002ef000, 0xc2000001e0, 0xc2000fa8a0, 0xc2000001d8, ...)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/builder.go:88 +0x30f
 github.com/mitchellh/packer/packer/plugin.(*cmdBuilder).Run(0xc2001ad480, 0xc2002ef000, 0xc2000001e0, 0xc2000fa8a0, 0xc2000001d8, ...)
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/plugin/builder.go:28 +0xeb
 github.com/mitchellh/packer/packer/rpc.func·002()
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/builder.go:140 +0x1a9
 created by github.com/mitchellh/packer/packer/rpc.(*BuilderServer).Run
    /Users/mitchellh/code/go/src/github.com/mitchellh/packer/packer/rpc/builder.go:158 +0x1c8