go segfault

unexpected fault address 0xffffffffcacb9349
fatal error: fault
[signal 0xb code=0x1 addr=0xffffffffcacb9349 pc=0x5091a2]

goroutine 15 [running]:
runtime.throw(0x957648, 0x5)
        /usr/local/go/src/runtime/panic.go:527 +0x90 fp=0xc8200c46f0 sp=0xc8200c46d8
runtime.sigpanic()
        /usr/local/go/src/runtime/sigpanic_unix.go:27 +0x2ab fp=0xc8200c4740 sp=0xc8200c46f0
unicode/utf8.Valid(0xc82030a13b, 0xf, 0xbc5, 0xc8200c47c0)
        /usr/local/go/src/unicode/utf8/utf8.go:397 +0x2 fp=0xc8200c4748 sp=0xc8200c4740
encoding/asn1.parseUTF8String(0xc82030a13b, 0xf, 0xbc5, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/encoding/asn1/asn1.go:393 +0x5e fp=0xc8200c47a8 sp=0xc8200c4748
encoding/asn1.parseField(0x7e7c00, 0xc82000ad38, 0xd4, 0xc82030a134, 0x16, 0xbcc, 0x5, 0x0, 0x0, 0x0, ...)
        /usr/local/go/src/encoding/asn1/asn1.go:607 +0xad0 fp=0xc8200c4f20 sp=0xc8200c47a8
encoding/asn1.parseField(0x8bd820, 0xc82000ad20, 0xd9, 0xc82030a132, 0x18, 0xbce, 0x0, 0x0, 0x0, 0x0, ...)
        /usr/local/go/src/encoding/asn1/asn1.go:818 +0x3181 fp=0xc8200c5698 sp=0xc8200c4f20
encoding/asn1.parseSequenceOf(0xc82030a132, 0x18, 0xbce, 0x7ffb4a44b080, 0x7ed6c0, 0x7ffb4a44b080, 0x8bd820, 0x7ed6c0, 0xc820011ae0, 0x57, ...)
        /usr/local/go/src/encoding/asn1/asn1.go:528 +0x452 fp=0xc8200c57d0 sp=0xc8200c5698
encoding/asn1.parseField(0x7ed6c0, 0xc82027eb60, 0xd7, 0xc82030a08c, 0xbe, 0xc74, 0xa4, 0x0, 0x0, 0x0, ...)
        /usr/local/go/src/encoding/asn1/asn1.go:834 +0x2705 fp=0xc8200c5f48 sp=0xc8200c57d0
encoding/asn1.parseSequenceOf(0xc82030a08c, 0xbe, 0xc74, 0x7ffb4a44b080, 0x7ed640, 0x7ffb4a44b080, 0x7ed6c0, 0x7ed640, 0xc820011820, 0x57, ...)
        /usr/local/go/src/encoding/asn1/asn1.go:528 +0x452 fp=0xc8200c6080 sp=0xc8200c5f48
encoding/asn1.parseField(0x7ed640, 0xc820011800, 0xd7, 0xc82030a089, 0xc1, 0xc77, 0x0, 0x0, 0x0, 0x0, ...)
        /usr/local/go/src/encoding/asn1/asn1.go:834 +0x2705 fp=0xc8200c67f8 sp=0xc8200c6080
encoding/asn1.UnmarshalWithParams(0xc82030a089, 0xc1, 0xc77, 0x7c3ea0, 0xc820011800, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /usr/local/go/src/encoding/asn1/asn1.go:957 +0x16e fp=0xc8200c68e0 sp=0xc8200c67f8
encoding/asn1.Unmarshal(0xc82030a089, 0xc1, 0xc77, 0x7c3ea0, 0xc820011800, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/encoding/asn1/asn1.go:950 +0x8f fp=0xc8200c6948 sp=0xc8200c68e0
crypto/x509.parseCertificate(0xc820310000, 0x537, 0x0, 0x0)
        /usr/local/go/src/crypto/x509/x509.go:917 +0x577 fp=0xc8200c72b0 sp=0xc8200c6948
crypto/x509.ParseCertificate(0xc82030a00a, 0x537, 0xcf6, 0xc820010ea0, 0x0, 0x0)
        /usr/local/go/src/crypto/x509/x509.go:1159 +0x19e fp=0xc8200c7358 sp=0xc8200c72b0
crypto/tls.(*clientHandshakeState).doFullHandshake(0xc8200c7e48, 0x0, 0x0)
        /usr/local/go/src/crypto/tls/handshake_client.go:249 +0x26d fp=0xc8200c7a10 sp=0xc8200c7358
crypto/tls.(*Conn).clientHandshake(0xc820304000, 0x0, 0x0)
        /usr/local/go/src/crypto/tls/handshake_client.go:206 +0x164e fp=0xc8200c7ef8 sp=0xc8200c7a10
crypto/tls.(*Conn).Handshake(0xc820304000, 0x0, 0x0)
        /usr/local/go/src/crypto/tls/conn.go:974 +0xec fp=0xc8200c7f38 sp=0xc8200c7ef8
net/http.(*Transport).dialConn.func3(0xc820304000, 0xc820013200, 0xc820016f60)
        /usr/local/go/src/net/http/transport.go:662 +0x21 fp=0xc8200c7f78 sp=0xc8200c7f38
runtime.goexit()
        /usr/local/go/src/runtime/asm_amd64.s:1696 +0x1 fp=0xc8200c7f80 sp=0xc8200c7f78
created by net/http.(*Transport).dialConn
        /usr/local/go/src/net/http/transport.go:667 +0x7bc

goroutine 1 [semacquire]:
sync.runtime_Semacquire(0xc82000e4bc)
        /usr/local/go/src/runtime/sema.go:43 +0x26
sync.(*WaitGroup).Wait(0xc82000e4b0)
        /usr/local/go/src/sync/waitgroup.go:126 +0xb4
github.com/mitchellh/packer/command.BuildCommand.Run(0xc820137740, 0x7ffb4a4073e0, 0xc820139440, 0x7ffb4a407398, 0xc820137700, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/command/build.go:189 +0x1dca
github.com/mitchellh/packer/command.(*BuildCommand).Run(0xc82014e690, 0xc82007c170, 0x1, 0x1, 0xc8201402f8)
        <autogenerated>:1 +0xd1
github.com/mitchellh/cli.(*CLI).Run(0xc82019c000, 0xc82019c000, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/cli/cli.go:112 +0x655
main.wrappedMain(0x0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/main.go:187 +0x139f
main.realMain(0x0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/main.go:91 +0xa88
main.main()
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/main.go:26 +0x18

goroutine 19 [syscall]:
os/signal.loop()
        /usr/local/go/src/os/signal/signal_unix.go:22 +0x18
created by os/signal.init.1
        /usr/local/go/src/os/signal/signal_unix.go:28 +0x37

goroutine 33 [syscall]:
syscall.Syscall(0x0, 0x0, 0xc820166000, 0x8000, 0x28004369d1, 0x19, 0x1)
        /usr/local/go/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0x0, 0xc820166000, 0x8000, 0x8000, 0x7ffb4a487050, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0x0, 0xc820166000, 0x8000, 0x8000, 0xc820166000, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_unix.go:160 +0x4d
os.(*File).read(0xc82008e000, 0xc820166000, 0x8000, 0x8000, 0x88caa0, 0x0, 0x0)
        /usr/local/go/src/os/file_unix.go:211 +0x53
os.(*File).Read(0xc82008e000, 0xc820166000, 0x8000, 0x8000, 0x8000, 0x0, 0x0)
        /usr/local/go/src/os/file.go:95 +0x8a
io.copyBuffer(0x7ffb4a44b198, 0xc82013a030, 0x7ffb4a44b270, 0xc82008e000, 0xc820166000, 0x8000, 0x8000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:381 +0x247
io.Copy(0x7ffb4a44b198, 0xc82013a030, 0x7ffb4a44b270, 0xc82008e000, 0x95b850, 0x0, 0x0)
        /usr/local/go/src/io/io.go:351 +0x64
main.setupStdin.func1(0xc82013a030, 0xc82008e000)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/stdin.go:23 +0xb4
created by main.setupStdin
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/stdin.go:24 +0x76

goroutine 34 [select, locked to thread]:
runtime.gopark(0xa3ca90, 0xc820158728, 0x95a538, 0x6, 0x18, 0x2)
        /usr/local/go/src/runtime/proc.go:185 +0x163
runtime.selectgoImpl(0xc820158728, 0x0, 0x18)
        /usr/local/go/src/runtime/select.go:392 +0xa64
runtime.selectgo(0xc820158728)
        /usr/local/go/src/runtime/select.go:212 +0x12
runtime.ensureSigM.func1()
        /usr/local/go/src/runtime/signal1_unix.go:227 +0x353
runtime.goexit()
        /usr/local/go/src/runtime/asm_amd64.s:1696 +0x1

goroutine 35 [chan receive]:
main.setupStdin.func2(0xc8201440c0, 0xc82013a030)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/stdin.go:34 +0x93
created by main.setupStdin
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/stdin.go:36 +0x13c

goroutine 36 [select]:
net/http.(*Transport).getConn(0xc8200a2090, 0xc8201ce000, 0x0, 0xc8201b41b0, 0x5, 0xc8201b2080, 0x20, 0x0, 0x0, 0x0)
        /usr/local/go/src/net/http/transport.go:554 +0x663
net/http.(*Transport).RoundTrip(0xc8200a2090, 0xc8201ce000, 0xd0, 0x0, 0x0)
        /usr/local/go/src/net/http/transport.go:228 +0x4ac
net/http.send(0xc8201ce000, 0x7ffb4a44b4b0, 0xc8200a2090, 0xc8201b4240, 0x0, 0x0)
        /usr/local/go/src/net/http/client.go:220 +0x52c
net/http.(*Client).send(0xbd6900, 0xc8201ce000, 0x85, 0x0, 0x0)
        /usr/local/go/src/net/http/client.go:143 +0x15a
net/http.(*Client).doFollowingRedirects(0xbd6900, 0xc8201ce000, 0xa3c670, 0x0, 0x0, 0x0)
        /usr/local/go/src/net/http/client.go:380 +0xbc0
net/http.(*Client).Do(0xbd6900, 0xc8201ce000, 0xa, 0x0, 0x0)
        /usr/local/go/src/net/http/client.go:175 +0x9c
github.com/hashicorp/go-checkpoint.Check(0xc8201d5f18, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-checkpoint/checkpoint.go:139 +0xa54
main.runCheckpoint(0xc820132330)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/checkpoint.go:51 +0x41a
created by main.wrappedMain
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/main.go:121 +0x7b1

goroutine 37 [semacquire]:
sync.runtime_Syncsemacquire(0xc82019e040)
        /usr/local/go/src/runtime/sema.go:237 +0x201
sync.(*Cond).Wait(0xc82019e030)
        /usr/local/go/src/sync/cond.go:62 +0x9b
io.(*pipe).read(0xc82019e000, 0xc8201a0000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:52 +0x2d2
io.(*PipeReader).Read(0xc82013a068, 0xc8201a0000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:134 +0x50
bufio.(*Scanner).Scan(0xc82013e380, 0x0)
        /usr/local/go/src/bufio/scan.go:180 +0x877
github.com/mitchellh/packer/command.(*Meta).FlagSet.func1(0xc82013e380, 0xc82014e700)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/command/meta.go:131 +0x25
created by github.com/mitchellh/packer/command.(*Meta).FlagSet
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/command/meta.go:134 +0x56e

goroutine 49 [chan receive]:
net/http.(*Transport).dialConn(0xc8200a2090, 0x0, 0xc8201b41b0, 0x5, 0xc8201b2080, 0x20, 0x0, 0x0, 0x0)
        /usr/local/go/src/net/http/transport.go:668 +0x7f8
net/http.(*Transport).getConn.func4(0xc8200a2090, 0x0, 0xc8201b41b0, 0x5, 0xc8201b2080, 0x20, 0xc8201b0060)
        /usr/local/go/src/net/http/transport.go:549 +0x66
created by net/http.(*Transport).getConn
        /usr/local/go/src/net/http/transport.go:551 +0x265

goroutine 22 [IO wait]:
net.runtime_pollWait(0x7ffb4a3cbe80, 0x72, 0xc8200780a0)
        /usr/local/go/src/runtime/netpoll.go:157 +0x60
net.(*pollDesc).Wait(0xc8200dd410, 0x72, 0x0, 0x0)
        /usr/local/go/src/net/fd_poll_runtime.go:73 +0x3a
net.(*pollDesc).WaitRead(0xc8200dd410, 0x0, 0x0)
        /usr/local/go/src/net/fd_poll_runtime.go:78 +0x36
net.(*netFD).Read(0xc8200dd3b0, 0xc8200df000, 0x1000, 0x1000, 0x0, 0x7ffb4a447028, 0xc8200780a0)
        /usr/local/go/src/net/fd_unix.go:232 +0x23a
net.(*conn).Read(0xc82008e0c0, 0xc8200df000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/net/net.go:172 +0xe4
bufio.(*Reader).fill(0xc8200762a0)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).Read(0xc8200762a0, 0xc8200e5c40, 0xc, 0xc, 0xc8200e5c42, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:207 +0x260
io.ReadAtLeast(0x7ffb4a44be48, 0xc8200762a0, 0xc8200e5c40, 0xc, 0xc, 0xc, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:298 +0xe6
io.ReadFull(0x7ffb4a44be48, 0xc8200762a0, 0xc8200e5c40, 0xc, 0xc, 0xc, 0x0, 0x0)
        /usr/local/go/src/io/io.go:316 +0x62
github.com/hashicorp/yamux.(*Session).recvLoop(0xc82010d080, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:398 +0x11e
github.com/hashicorp/yamux.(*Session).recv(0xc82010d080)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:386 +0x21
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:104 +0x4b1

goroutine 54 [select]:
github.com/hashicorp/yamux.(*Stream).Read(0xc82020a140, 0xc8202d9000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/stream.go:125 +0x3ae
bufio.(*Reader).fill(0xc8201b0600)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadByte(0xc8201b0600, 0xc8201aac20, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:229 +0x7a
github.com/hashicorp/go-msgpack/codec.(*ioDecReader).readn1(0xc8201aec30, 0x6f94c1)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:90 +0x42
github.com/hashicorp/go-msgpack/codec.(*msgpackDecDriver).initReadNext(0xc8201b2580)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/msgpack.go:540 +0x41
github.com/hashicorp/go-msgpack/codec.(*Decoder).decode(0xc8201b0660, 0x7cd560, 0xc8201aef00)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:635 +0x70
github.com/hashicorp/go-msgpack/codec.(*Decoder).Decode(0xc8201b0660, 0x7cd560, 0xc8201aef00, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:630 +0x74
github.com/hashicorp/go-msgpack/codec.(*rpcCodec).read(0xc82017a840, 0x7cd560, 0xc8201aef00, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:88 +0xd2
github.com/hashicorp/go-msgpack/codec.(*goRpcCodec).ReadResponseHeader(0xc82017a840, 0xc8201aef00, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:123 +0x54
net/rpc.(*Client).input(0xc8201b06c0)
        /usr/local/go/src/net/rpc/client.go:109 +0xbf
created by net/rpc.NewClientWithCodec
        /usr/local/go/src/net/rpc/client.go:201 +0xd2

goroutine 21 [chan receive]:
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func4.1(0xc820145800)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:294 +0x52
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start.func4
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:296 +0x35

goroutine 46 [syscall]:
syscall.Syscall(0x0, 0x8, 0xc820224000, 0x8000, 0xa, 0x1a, 0x4e9ef0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0x8, 0xc820224000, 0x8000, 0x8000, 0x432362, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0x8, 0xc820224000, 0x8000, 0x8000, 0x458900, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_unix.go:160 +0x4d
os.(*File).read(0xc82013a108, 0xc820224000, 0x8000, 0x8000, 0xc820224000, 0x0, 0x0)
        /usr/local/go/src/os/file_unix.go:211 +0x53
os.(*File).Read(0xc82013a108, 0xc820224000, 0x8000, 0x8000, 0x23, 0x0, 0x0)
        /usr/local/go/src/os/file.go:95 +0x8a
io.copyBuffer(0x7ffb4a407540, 0xc82013a0e8, 0x7ffb4a44b270, 0xc82013a108, 0xc820224000, 0x8000, 0x8000, 0x23, 0x0, 0x0)
        /usr/local/go/src/io/io.go:381 +0x247
io.Copy(0x7ffb4a407540, 0xc82013a0e8, 0x7ffb4a44b270, 0xc82013a108, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:351 +0x64
os/exec.(*Cmd).writerDescriptor.func1(0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:232 +0x8b
os/exec.(*Cmd).Start.func1(0xc82020a000, 0xc8201d87a0)
        /usr/local/go/src/os/exec/exec.go:340 +0x1d
created by os/exec.(*Cmd).Start
        /usr/local/go/src/os/exec/exec.go:341 +0x96d

goroutine 47 [syscall]:
syscall.Syscall(0x0, 0xa, 0xc82021c000, 0x8000, 0xa, 0x1a, 0x4e9ef0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0xa, 0xc82021c000, 0x8000, 0x8000, 0x432362, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0xa, 0xc82021c000, 0x8000, 0x8000, 0x458900, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_unix.go:160 +0x4d
os.(*File).read(0xc82013a120, 0xc82021c000, 0x8000, 0x8000, 0xc82021c000, 0x0, 0x0)
        /usr/local/go/src/os/file_unix.go:211 +0x53
os.(*File).Read(0xc82013a120, 0xc82021c000, 0x8000, 0x8000, 0xd2, 0x0, 0x0)
        /usr/local/go/src/os/file.go:95 +0x8a
io.copyBuffer(0x7ffb4a407540, 0xc82013a0f8, 0x7ffb4a44b270, 0xc82013a120, 0xc82021c000, 0x8000, 0x8000, 0x6a9, 0x0, 0x0)
        /usr/local/go/src/io/io.go:381 +0x247
io.Copy(0x7ffb4a407540, 0xc82013a0f8, 0x7ffb4a44b270, 0xc82013a120, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:351 +0x64
os/exec.(*Cmd).writerDescriptor.func1(0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:232 +0x8b
os/exec.(*Cmd).Start.func1(0xc82020a000, 0xc8201d8800)
        /usr/local/go/src/os/exec/exec.go:340 +0x1d
created by os/exec.(*Cmd).Start
        /usr/local/go/src/os/exec/exec.go:341 +0x96d

goroutine 48 [syscall]:
syscall.Syscall6(0x3d, 0x54b8, 0xc82021957c, 0x0, 0xc820150ab0, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:44 +0x5
syscall.wait4(0x54b8, 0xc82021957c, 0x0, 0xc820150ab0, 0x90, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:172 +0x72
syscall.Wait4(0x54b8, 0xc8202195c4, 0x0, 0xc820150ab0, 0x0, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_linux.go:256 +0x55
os.(*Process).wait(0xc8201d8c00, 0x0, 0x0, 0x0)
        /usr/local/go/src/os/exec_unix.go:22 +0x105
os.(*Process).Wait(0xc8201d8c00, 0x0, 0x0, 0x0)
        /usr/local/go/src/os/doc.go:45 +0x2d
os/exec.(*Cmd).Wait(0xc82020a000, 0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:380 +0x211
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func2(0xc82013a0f8, 0xc82013a0e8, 0xc82020a000, 0xc8201457a0, 0xc8202042d0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:253 +0x7b
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:266 +0xf73

goroutine 65 [semacquire]:
sync.runtime_Syncsemacquire(0xc82019e280)
        /usr/local/go/src/runtime/sema.go:237 +0x201
sync.(*Cond).Wait(0xc82019e270)
        /usr/local/go/src/sync/cond.go:62 +0x9b
io.(*pipe).read(0xc82019e240, 0xc82001f000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:52 +0x2d2
io.(*PipeReader).Read(0xc82013a0f0, 0xc82001f000, 0x1000, 0x1000, 0x4f6c4d, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:134 +0x50
bufio.(*Reader).fill(0xc820048ee0)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadSlice(0xc820048ee0, 0x4ea00a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:328 +0x21a
bufio.(*Reader).ReadBytes(0xc820048ee0, 0xc82009000a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:406 +0xa9
bufio.(*Reader).ReadString(0xc820048ee0, 0xa, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:446 +0x4d
github.com/mitchellh/packer/packer/plugin.(*Client).logStderr(0xc8202042d0, 0x7ffb4a407518, 0xc82013a0f0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:343 +0xac
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:269 +0xfd9

goroutine 66 [semacquire]:
sync.runtime_Syncsemacquire(0xc82019e1c0)
        /usr/local/go/src/runtime/sema.go:237 +0x201
sync.(*Cond).Wait(0xc82019e1b0)
        /usr/local/go/src/sync/cond.go:62 +0x9b
io.(*pipe).read(0xc82019e180, 0xc82022c000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:52 +0x2d2
io.(*PipeReader).Read(0xc82013a0e0, 0xc82022c000, 0x1000, 0x1000, 0x23, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:134 +0x50
bufio.(*Reader).fill(0xc8201b6ee8)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadSlice(0xc8201b6ee8, 0xa, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:328 +0x21a
bufio.(*Reader).ReadBytes(0xc8201b6ee8, 0xc82014580a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:406 +0xa9
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func3(0xc820145800, 0xc82013a0e0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:279 +0x107
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:288 +0x1026

goroutine 23 [select]:
github.com/hashicorp/yamux.(*Session).send(0xc82010d080)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:348 +0x5e1
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:105 +0x4d3

goroutine 24 [select]:
github.com/hashicorp/yamux.(*Session).keepalive(0xc82010d080)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:287 +0x107
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:107 +0x506

goroutine 25 [select]:
github.com/hashicorp/yamux.(*Session).AcceptStream(0xc82010d080, 0xa3c220, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:191 +0x19d
github.com/mitchellh/packer/packer/rpc.(*muxBroker).Run(0xc82012c160)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/mux_broker.go:126 +0x34
created by github.com/mitchellh/packer/packer/rpc.NewClient
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/client.go:25 +0x94

goroutine 26 [select]:
github.com/hashicorp/yamux.(*Stream).Read(0xc8200b8b40, 0xc820259000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/stream.go:125 +0x3ae
bufio.(*Reader).fill(0xc820076720)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadByte(0xc820076720, 0xc8201b2680, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:229 +0x7a
github.com/hashicorp/go-msgpack/codec.(*ioDecReader).readn1(0xc82012e2a0, 0xc820076780)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:90 +0x42
github.com/hashicorp/go-msgpack/codec.(*msgpackDecDriver).initReadNext(0xc82012c220)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/msgpack.go:540 +0x41
github.com/hashicorp/go-msgpack/codec.(*Decoder).decode(0xc820076780, 0x7cd560, 0xc82000a120)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:635 +0x70
github.com/hashicorp/go-msgpack/codec.(*Decoder).Decode(0xc820076780, 0x7cd560, 0xc82000a120, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:630 +0x74
github.com/hashicorp/go-msgpack/codec.(*rpcCodec).read(0xc82012a540, 0x7cd560, 0xc82000a120, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:88 +0xd2
github.com/hashicorp/go-msgpack/codec.(*goRpcCodec).ReadResponseHeader(0xc82012a540, 0xc82000a120, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:123 +0x54
net/rpc.(*Client).input(0xc8200767e0)
        /usr/local/go/src/net/rpc/client.go:109 +0xbf
created by net/rpc.NewClientWithCodec
        /usr/local/go/src/net/rpc/client.go:201 +0xd2

goroutine 27 [syscall]:
syscall.Syscall(0x0, 0xb, 0xc82025a000, 0x8000, 0xa, 0x1a, 0x4e9ef0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0xb, 0xc82025a000, 0x8000, 0x8000, 0x432362, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0xb, 0xc82025a000, 0x8000, 0x8000, 0x458900, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_unix.go:160 +0x4d
os.(*File).read(0xc82008e0f0, 0xc82025a000, 0x8000, 0x8000, 0xc82025a000, 0x0, 0x0)
        /usr/local/go/src/os/file_unix.go:211 +0x53
os.(*File).Read(0xc82008e0f0, 0xc82025a000, 0x8000, 0x8000, 0x23, 0x0, 0x0)
        /usr/local/go/src/os/file.go:95 +0x8a
io.copyBuffer(0x7ffb4a407540, 0xc82008e0d0, 0x7ffb4a44b270, 0xc82008e0f0, 0xc82025a000, 0x8000, 0x8000, 0x23, 0x0, 0x0)
        /usr/local/go/src/io/io.go:381 +0x247
io.Copy(0x7ffb4a407540, 0xc82008e0d0, 0x7ffb4a44b270, 0xc82008e0f0, 0xc800000001, 0x0, 0x0)
        /usr/local/go/src/io/io.go:351 +0x64
os/exec.(*Cmd).writerDescriptor.func1(0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:232 +0x8b
os/exec.(*Cmd).Start.func1(0xc8200b8c80, 0xc82012c300)
        /usr/local/go/src/os/exec/exec.go:340 +0x1d
created by os/exec.(*Cmd).Start
        /usr/local/go/src/os/exec/exec.go:341 +0x96d

goroutine 28 [syscall]:
syscall.Syscall(0x0, 0xd, 0xc820276000, 0x8000, 0xa, 0x1a, 0x4e9ef0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0xd, 0xc820276000, 0x8000, 0x8000, 0x432362, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0xd, 0xc820276000, 0x8000, 0x8000, 0x458900, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_unix.go:160 +0x4d
os.(*File).read(0xc82008e108, 0xc820276000, 0x8000, 0x8000, 0xc820276000, 0x0, 0x0)
        /usr/local/go/src/os/file_unix.go:211 +0x53
os.(*File).Read(0xc82008e108, 0xc820276000, 0x8000, 0x8000, 0x33, 0x0, 0x0)
        /usr/local/go/src/os/file.go:95 +0x8a
io.copyBuffer(0x7ffb4a407540, 0xc82008e0e0, 0x7ffb4a44b270, 0xc82008e108, 0xc820276000, 0x8000, 0x8000, 0x104, 0x0, 0x0)
        /usr/local/go/src/io/io.go:381 +0x247
io.Copy(0x7ffb4a407540, 0xc82008e0e0, 0x7ffb4a44b270, 0xc82008e108, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:351 +0x64
os/exec.(*Cmd).writerDescriptor.func1(0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:232 +0x8b
os/exec.(*Cmd).Start.func1(0xc8200b8c80, 0xc82012c360)
        /usr/local/go/src/os/exec/exec.go:340 +0x1d
created by os/exec.(*Cmd).Start
        /usr/local/go/src/os/exec/exec.go:341 +0x96d

goroutine 29 [syscall]:
syscall.Syscall6(0x3d, 0x54c5, 0xc82002ad7c, 0x0, 0xc820150b40, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:44 +0x5
syscall.wait4(0x54c5, 0xc82002ad7c, 0x0, 0xc820150b40, 0x90, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:172 +0x72
syscall.Wait4(0x54c5, 0xc82002adc4, 0x0, 0xc820150b40, 0x0, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_linux.go:256 +0x55
os.(*Process).wait(0xc82012c760, 0x0, 0x0, 0x0)
        /usr/local/go/src/os/exec_unix.go:22 +0x105
os.(*Process).Wait(0xc82012c760, 0x0, 0x0, 0x0)
        /usr/local/go/src/os/doc.go:45 +0x2d
os/exec.(*Cmd).Wait(0xc8200b8c80, 0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:380 +0x211
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func2(0xc82008e0e0, 0xc82008e0d0, 0xc8200b8c80, 0xc820076ba0, 0xc82012e330)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:253 +0x7b
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:266 +0xf73

goroutine 30 [semacquire]:
sync.runtime_Syncsemacquire(0xc8200e0400)
        /usr/local/go/src/runtime/sema.go:237 +0x201
sync.(*Cond).Wait(0xc8200e03f0)
        /usr/local/go/src/sync/cond.go:62 +0x9b
io.(*pipe).read(0xc8200e03c0, 0xc820263000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:52 +0x2d2
io.(*PipeReader).Read(0xc82008e0d8, 0xc820263000, 0x1000, 0x1000, 0x4f6c4d, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:134 +0x50
bufio.(*Reader).fill(0xc820269ee0)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadSlice(0xc820269ee0, 0x4ea00a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:328 +0x21a
bufio.(*Reader).ReadBytes(0xc820269ee0, 0xc82009000a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:406 +0xa9
bufio.(*Reader).ReadString(0xc820269ee0, 0xa, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:446 +0x4d
github.com/mitchellh/packer/packer/plugin.(*Client).logStderr(0xc82012e330, 0x7ffb4a407518, 0xc82008e0d8)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:343 +0xac
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:269 +0xfd9

goroutine 31 [semacquire]:
sync.runtime_Syncsemacquire(0xc8200e0340)
        /usr/local/go/src/runtime/sema.go:237 +0x201
sync.(*Cond).Wait(0xc8200e0330)
        /usr/local/go/src/sync/cond.go:62 +0x9b
io.(*pipe).read(0xc8200e0300, 0xc820262000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:52 +0x2d2
io.(*PipeReader).Read(0xc82008e0c8, 0xc820262000, 0x1000, 0x1000, 0x23, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:134 +0x50
bufio.(*Reader).fill(0xc820268ee8)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadSlice(0xc820268ee8, 0xa, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:328 +0x21a
bufio.(*Reader).ReadBytes(0xc820268ee8, 0xc820076c0a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:406 +0xa9
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func3(0xc820076c00, 0xc82008e0c8)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:279 +0x107
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:288 +0x1026

goroutine 3 [chan receive]:
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func4.1(0xc820076c00)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:294 +0x52
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start.func4
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:296 +0x35

goroutine 4 [IO wait]:
net.runtime_pollWait(0x7ffb4a3cbdc0, 0x72, 0xc8200780a0)
        /usr/local/go/src/runtime/netpoll.go:157 +0x60
net.(*pollDesc).Wait(0xc82001c0d0, 0x72, 0x0, 0x0)
        /usr/local/go/src/net/fd_poll_runtime.go:73 +0x3a
net.(*pollDesc).WaitRead(0xc82001c0d0, 0x0, 0x0)
        /usr/local/go/src/net/fd_poll_runtime.go:78 +0x36
net.(*netFD).Read(0xc82001c070, 0xc820280000, 0x1000, 0x1000, 0x0, 0x7ffb4a447028, 0xc8200780a0)
        /usr/local/go/src/net/fd_unix.go:232 +0x23a
net.(*conn).Read(0xc820030008, 0xc820280000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/net/net.go:172 +0xe4
bufio.(*Reader).fill(0xc8200161e0)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).Read(0xc8200161e0, 0xc8201aa740, 0xc, 0xc, 0xc8201aa742, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:207 +0x260
io.ReadAtLeast(0x7ffb4a44be48, 0xc8200161e0, 0xc8201aa740, 0xc, 0xc, 0xc, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:298 +0xe6
io.ReadFull(0x7ffb4a44be48, 0xc8200161e0, 0xc8201aa740, 0xc, 0xc, 0xc, 0x0, 0x0)
        /usr/local/go/src/io/io.go:316 +0x62
github.com/hashicorp/yamux.(*Session).recvLoop(0xc820288000, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:398 +0x11e
github.com/hashicorp/yamux.(*Session).recv(0xc820288000)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:386 +0x21
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:104 +0x4b1

goroutine 5 [select]:
github.com/hashicorp/yamux.(*Session).send(0xc820288000)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:348 +0x5e1
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:105 +0x4d3

goroutine 6 [select]:
github.com/hashicorp/yamux.(*Session).keepalive(0xc820288000)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:287 +0x107
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:107 +0x506

goroutine 7 [select]:
github.com/hashicorp/yamux.(*Session).AcceptStream(0xc820288000, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:191 +0x19d
github.com/mitchellh/packer/packer/rpc.(*muxBroker).Run(0xc8200103c0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/mux_broker.go:126 +0x34
created by github.com/mitchellh/packer/packer/rpc.NewClient
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/client.go:25 +0x94

goroutine 8 [select]:
github.com/hashicorp/yamux.(*Stream).Read(0xc82028a000, 0xc82028e000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/stream.go:125 +0x3ae
bufio.(*Reader).fill(0xc8200166c0)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadByte(0xc8200166c0, 0xc8201aab10, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:229 +0x7a
github.com/hashicorp/go-msgpack/codec.(*ioDecReader).readn1(0xc82000a2d0, 0x6f94c1)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:90 +0x42
github.com/hashicorp/go-msgpack/codec.(*msgpackDecDriver).initReadNext(0xc8200104a0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/msgpack.go:540 +0x41
github.com/hashicorp/go-msgpack/codec.(*Decoder).decode(0xc820016720, 0x7cd560, 0xc820204510)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:635 +0x70
github.com/hashicorp/go-msgpack/codec.(*Decoder).Decode(0xc820016720, 0x7cd560, 0xc820204510, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:630 +0x74
github.com/hashicorp/go-msgpack/codec.(*rpcCodec).read(0xc820012640, 0x7cd560, 0xc820204510, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:88 +0xd2
github.com/hashicorp/go-msgpack/codec.(*goRpcCodec).ReadResponseHeader(0xc820012640, 0xc820204510, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:123 +0x54
net/rpc.(*Client).input(0xc820016780)
        /usr/local/go/src/net/rpc/client.go:109 +0xbf
created by net/rpc.NewClientWithCodec
        /usr/local/go/src/net/rpc/client.go:201 +0xd2

goroutine 32 [syscall]:
syscall.Syscall(0x0, 0xe, 0xc8202ae000, 0x8000, 0xa, 0x1a, 0x4e9ef0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0xe, 0xc8202ae000, 0x8000, 0x8000, 0x432362, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0xe, 0xc8202ae000, 0x8000, 0x8000, 0x458900, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_unix.go:160 +0x4d
os.(*File).read(0xc820030038, 0xc8202ae000, 0x8000, 0x8000, 0xc8202ae000, 0x0, 0x0)
        /usr/local/go/src/os/file_unix.go:211 +0x53
os.(*File).Read(0xc820030038, 0xc8202ae000, 0x8000, 0x8000, 0x23, 0x0, 0x0)
        /usr/local/go/src/os/file.go:95 +0x8a
io.copyBuffer(0x7ffb4a407540, 0xc820030018, 0x7ffb4a44b270, 0xc820030038, 0xc8202ae000, 0x8000, 0x8000, 0x23, 0x0, 0x0)
        /usr/local/go/src/io/io.go:381 +0x247
io.Copy(0x7ffb4a407540, 0xc820030018, 0x7ffb4a44b270, 0xc820030038, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:351 +0x64
os/exec.(*Cmd).writerDescriptor.func1(0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:232 +0x8b
os/exec.(*Cmd).Start.func1(0xc82028a140, 0xc8200105e0)
        /usr/local/go/src/os/exec/exec.go:340 +0x1d
created by os/exec.(*Cmd).Start
        /usr/local/go/src/os/exec/exec.go:341 +0x96d

goroutine 81 [syscall]:
syscall.Syscall(0x0, 0x10, 0xc8202c8000, 0x8000, 0xa, 0x1a, 0x4e9ef0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0x10, 0xc8202c8000, 0x8000, 0x8000, 0x432362, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0x10, 0xc8202c8000, 0x8000, 0x8000, 0x458900, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_unix.go:160 +0x4d
os.(*File).read(0xc820030050, 0xc8202c8000, 0x8000, 0x8000, 0xc8202c8000, 0x0, 0x0)
        /usr/local/go/src/os/file_unix.go:211 +0x53
os.(*File).Read(0xc820030050, 0xc8202c8000, 0x8000, 0x8000, 0x33, 0x0, 0x0)
        /usr/local/go/src/os/file.go:95 +0x8a
io.copyBuffer(0x7ffb4a407540, 0xc820030028, 0x7ffb4a44b270, 0xc820030050, 0xc8202c8000, 0x8000, 0x8000, 0x104, 0x0, 0x0)
        /usr/local/go/src/io/io.go:381 +0x247
io.Copy(0x7ffb4a407540, 0xc820030028, 0x7ffb4a44b270, 0xc820030050, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:351 +0x64
os/exec.(*Cmd).writerDescriptor.func1(0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:232 +0x8b
os/exec.(*Cmd).Start.func1(0xc82028a140, 0xc820010640)
        /usr/local/go/src/os/exec/exec.go:340 +0x1d
created by os/exec.(*Cmd).Start
        /usr/local/go/src/os/exec/exec.go:341 +0x96d

goroutine 82 [syscall]:
syscall.Syscall6(0x3d, 0x54cf, 0xc82021457c, 0x0, 0xc820292120, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/syscall/asm_linux_amd64.s:44 +0x5
syscall.wait4(0x54cf, 0xc82021457c, 0x0, 0xc820292120, 0x90, 0x0, 0x0)
        /usr/local/go/src/syscall/zsyscall_linux_amd64.go:172 +0x72
syscall.Wait4(0x54cf, 0xc8202145c4, 0x0, 0xc820292120, 0x0, 0x0, 0x0)
        /usr/local/go/src/syscall/syscall_linux.go:256 +0x55
os.(*Process).wait(0xc82012c7c0, 0x0, 0x0, 0x0)
        /usr/local/go/src/os/exec_unix.go:22 +0x105
os.(*Process).Wait(0xc82012c7c0, 0x0, 0x0, 0x0)
        /usr/local/go/src/os/doc.go:45 +0x2d
os/exec.(*Cmd).Wait(0xc82028a140, 0x0, 0x0)
        /usr/local/go/src/os/exec/exec.go:380 +0x211
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func2(0xc820030028, 0xc820030018, 0xc82028a140, 0xc820076d20, 0xc82000a360)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:253 +0x7b
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:266 +0xf73

goroutine 83 [semacquire]:
sync.runtime_Syncsemacquire(0xc820294100)
        /usr/local/go/src/runtime/sema.go:237 +0x201
sync.(*Cond).Wait(0xc8202940f0)
        /usr/local/go/src/sync/cond.go:62 +0x9b
io.(*pipe).read(0xc8202940c0, 0xc8202b7000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:52 +0x2d2
io.(*PipeReader).Read(0xc820030020, 0xc8202b7000, 0x1000, 0x1000, 0x4f6c4d, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:134 +0x50
bufio.(*Reader).fill(0xc82026bee0)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadSlice(0xc82026bee0, 0x4ea00a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:328 +0x21a
bufio.(*Reader).ReadBytes(0xc82026bee0, 0xc82009000a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:406 +0xa9
bufio.(*Reader).ReadString(0xc82026bee0, 0xa, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:446 +0x4d
github.com/mitchellh/packer/packer/plugin.(*Client).logStderr(0xc82000a360, 0x7ffb4a407518, 0xc820030020)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:343 +0xac
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:269 +0xfd9

goroutine 84 [semacquire]:
sync.runtime_Syncsemacquire(0xc820294040)
        /usr/local/go/src/runtime/sema.go:237 +0x201
sync.(*Cond).Wait(0xc820294030)
        /usr/local/go/src/sync/cond.go:62 +0x9b
io.(*pipe).read(0xc820294000, 0xc8202b6000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:52 +0x2d2
io.(*PipeReader).Read(0xc820030010, 0xc8202b6000, 0x1000, 0x1000, 0x23, 0x0, 0x0)
        /usr/local/go/src/io/pipe.go:134 +0x50
bufio.(*Reader).fill(0xc82026aee8)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadSlice(0xc82026aee8, 0xa, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:328 +0x21a
bufio.(*Reader).ReadBytes(0xc82026aee8, 0xc820076d0a, 0x0, 0x0, 0x0, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:406 +0xa9
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func3(0xc820076d80, 0xc820030010)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:279 +0x107
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:288 +0x1026

goroutine 67 [chan receive]:
github.com/mitchellh/packer/packer/plugin.(*Client).Start.func4.1(0xc820076d80)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:294 +0x52
created by github.com/mitchellh/packer/packer/plugin.(*Client).Start.func4
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/client.go:296 +0x35

goroutine 68 [IO wait]:
net.runtime_pollWait(0x7ffb4a3cbd00, 0x72, 0xc8200780a0)
        /usr/local/go/src/runtime/netpoll.go:157 +0x60
net.(*pollDesc).Wait(0xc82014f6b0, 0x72, 0x0, 0x0)
        /usr/local/go/src/net/fd_poll_runtime.go:73 +0x3a
net.(*pollDesc).WaitRead(0xc82014f6b0, 0x0, 0x0)
        /usr/local/go/src/net/fd_poll_runtime.go:78 +0x36
net.(*netFD).Read(0xc82014f650, 0xc82022d000, 0x1000, 0x1000, 0x0, 0x7ffb4a447028, 0xc8200780a0)
        /usr/local/go/src/net/fd_unix.go:232 +0x23a
net.(*conn).Read(0xc82013a130, 0xc82022d000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /usr/local/go/src/net/net.go:172 +0xe4
bufio.(*Reader).fill(0xc820145980)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).Read(0xc820145980, 0xc8201aa750, 0xc, 0xc, 0xc8201aa752, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:207 +0x260
io.ReadAtLeast(0x7ffb4a44be48, 0xc820145980, 0xc8201aa750, 0xc, 0xc, 0xc, 0x0, 0x0, 0x0)
        /usr/local/go/src/io/io.go:298 +0xe6
io.ReadFull(0x7ffb4a44be48, 0xc820145980, 0xc8201aa750, 0xc, 0xc, 0xc, 0x0, 0x0)
        /usr/local/go/src/io/io.go:316 +0x62
github.com/hashicorp/yamux.(*Session).recvLoop(0xc82019c0b0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:398 +0x11e
github.com/hashicorp/yamux.(*Session).recv(0xc82019c0b0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:386 +0x21
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:104 +0x4b1

goroutine 69 [select]:
github.com/hashicorp/yamux.(*Session).send(0xc82019c0b0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:348 +0x5e1
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:105 +0x4d3

goroutine 70 [select]:
github.com/hashicorp/yamux.(*Session).keepalive(0xc82019c0b0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:287 +0x107
created by github.com/hashicorp/yamux.newSession
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:107 +0x506

goroutine 71 [select]:
github.com/hashicorp/yamux.(*Session).AcceptStream(0xc82019c0b0, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/session.go:191 +0x19d
github.com/mitchellh/packer/packer/rpc.(*muxBroker).Run(0xc8201d8d20)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/mux_broker.go:126 +0x34
created by github.com/mitchellh/packer/packer/rpc.NewClient
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/client.go:25 +0x94

goroutine 9 [chan receive]:
github.com/mitchellh/packer/command.BuildCommand.Run.func2(0xc820016ae0, 0xc82000e4a0, 0xc82000e4c0, 0x7ffb4a3cc210, 0xc8201ec0a0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/command/build.go:142 +0x40
created by github.com/mitchellh/packer/command.BuildCommand.Run
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/command/build.go:150 +0x19b0

goroutine 10 [chan receive]:
net/rpc.(*Client).Call(0xc8200767e0, 0x95ed40, 0xb, 0x7ed340, 0xc82000e570, 0x7d4640, 0xc82000e560, 0x0, 0x0)
        /usr/local/go/src/net/rpc/client.go:315 +0xcd
github.com/mitchellh/packer/packer/rpc.(*builder).Run(0xc8200e5cb0, 0x7ffb4a487118, 0xc820010b00, 0x7ffb4a487160, 0xc82000a720, 0x7ffb4a4073e0, 0xc820139440, 0x0, 0x0, 0x0, ...)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/builder.go:55 +0x2b9
github.com/mitchellh/packer/packer/plugin.(*cmdBuilder).Run(0xc82012c260, 0x7ffb4a487118, 0xc820010b00, 0x7ffb4a487160, 0xc82000a720, 0x7ffb4a4073e0, 0xc820139440, 0x0, 0x0, 0x0, ...)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/plugin/builder.go:28 +0xec
github.com/mitchellh/packer/packer.(*coreBuild).Run(0xc8201ec0a0, 0x7ffb4a3cc260, 0xc8201b25e0, 0x7ffb4a4073e0, 0xc820139440, 0x0, 0x0, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/build.go:206 +0xac3
github.com/mitchellh/packer/command.BuildCommand.Run.func3(0xc82000e4b0, 0xc8201aec90, 0xc82014e700, 0xc82000a660, 0xc82000a630, 0x7ffb4a3cc210, 0xc8201ec0a0)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/command/build.go:159 +0x244
created by github.com/mitchellh/packer/command.BuildCommand.Run
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/command/build.go:168 +0x1a23

goroutine 11 [select]:
github.com/hashicorp/yamux.(*Stream).Read(0xc8202f0000, 0xc8202f3000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/yamux/stream.go:125 +0x3ae
bufio.(*Reader).fill(0xc8201b0c00)
        /usr/local/go/src/bufio/bufio.go:97 +0x1e9
bufio.(*Reader).ReadByte(0xc8201b0c00, 0x8d6400, 0x0, 0x0)
        /usr/local/go/src/bufio/bufio.go:229 +0x7a
github.com/hashicorp/go-msgpack/codec.(*ioDecReader).readn1(0xc8201af4d0, 0x44cb17)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:90 +0x42
github.com/hashicorp/go-msgpack/codec.(*msgpackDecDriver).initReadNext(0xc8201b2c80)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/msgpack.go:540 +0x41
github.com/hashicorp/go-msgpack/codec.(*Decoder).decode(0xc8201b0c60, 0x7cd500, 0xc82012c880)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:635 +0x70
github.com/hashicorp/go-msgpack/codec.(*Decoder).Decode(0xc8201b0c60, 0x7cd500, 0xc82012c880, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/decode.go:630 +0x74
github.com/hashicorp/go-msgpack/codec.(*rpcCodec).read(0xc82017b000, 0x7cd500, 0xc82012c880, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:88 +0xd2
github.com/hashicorp/go-msgpack/codec.(*goRpcCodec).ReadRequestHeader(0xc82017b000, 0xc82012c880, 0x0, 0x0)
        /Users/cbednarski/code/golang/src/github.com/hashicorp/go-msgpack/codec/rpc.go:127 +0x54
net/rpc.(*Server).readRequestHeader(0xc820012a40, 0x7ffb4a3cc308, 0xc82017b000, 0x0, 0x0, 0xc82012c880, 0xc8202c7d00, 0x0, 0x0)
        /usr/local/go/src/net/rpc/server.go:576 +0x90
net/rpc.(*Server).readRequest(0xc820012a40, 0x7ffb4a3cc308, 0xc82017b000, 0xc820012a40, 0xc8201aad20, 0xc82027e280, 0x0, 0x0, 0x0, 0x0, ...)
        /usr/local/go/src/net/rpc/server.go:543 +0x8b
net/rpc.(*Server).ServeCodec(0xc820012a40, 0x7ffb4a3cc308, 0xc82017b000)
        /usr/local/go/src/net/rpc/server.go:462 +0x8c
github.com/mitchellh/packer/packer/rpc.(*Server).Serve(0xc820010b40)
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/server.go:141 +0x274
created by github.com/mitchellh/packer/packer/rpc.(*builder).Run
        /Users/cbednarski/code/golang/src/github.com/mitchellh/packer/packer/rpc/builder.go:52 +0x1ff