ng panics for hello world web server on OSX and Go 1.10

[nictuku]

$ uname -a
Darwin MacBook-Air-5.local 17.6.0 Darwin Kernel Version 17.6.0: Tue May  8 15:22:16 PDT 2018; root:xnu-4570.61.1~1/RELEASE_X86_64 x86_64

$ go version
go version go1.10 darwin/amd64

go get neugram.io/ng 
which ng
/Users/yves/bin/ng

$ cat web.ng 
#!/Users/yves/bin/ng

// Start a web server to serve files.
import "net/http"
pwd := $$ echo $PWD $$
h := http.FileServer(http.Dir(pwd))
http.ListenAndServe(":8080", h)

$ ./web.ng 
runtime: bad pointer in frame plugin.open at 0xc4206eacb8: 0x3
fatal error: invalid pointer found on stack

runtime stack:
runtime.throw(0x6623c5e, 0x1e)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/panic.go:619 +0x81 fp=0x700000fbd6f8 sp=0x700000fbd6d8 pc=0x620ad51
runtime.adjustpointers(0xc4206eac58, 0x700000fbd7f0, 0x700000fbdbc0, 0x47d62a8, 0x489df40)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/stack.go:592 +0x23e fp=0x700000fbd768 sp=0x700000fbd6f8 pc=0x6220e8e
runtime.adjustframe(0x700000fbdad0, 0x700000fbdbc0, 0x489df40)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/stack.go:663 +0x32c fp=0x700000fbd820 sp=0x700000fbd768 pc=0x62211dc
runtime.gentraceback(0xffffffffffffffff, 0xffffffffffffffff, 0x0, 0xc420000180, 0x0, 0x0, 0x7fffffff, 0x66327c0, 0x700000fbdbc0, 0x0, ...)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/traceback.go:355 +0x136c fp=0x700000fbdb38 sp=0x700000fbd820 pc=0x622a3cc
runtime.copystack(0xc420000180, 0x20000, 0x12498301)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/stack.go:891 +0x26e fp=0x700000fbdcf0 sp=0x700000fbdb38 pc=0x6221cce
runtime.newstack()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/stack.go:1063 +0x310 fp=0x700000fbde80 sp=0x700000fbdcf0 pc=0x62220e0
runtime: unexpected return pc for runtime.morestack called from 0x0
stack: frame={sp:0x700000fbde80, fp:0x700000fbde88} stack=[0x700000f3e290,0x700000fbde90)
0000700000fbdd80:  000000c420072180  00000074696e692e 
0000700000fbdd90:  0000000006bf9285  0000000004c02510 
0000700000fbdda0:  aafecb57dbd5000b  00001b0000001b00 
0000700000fbddb0:  00000000064a4c60 <plugin/unnamed-157e9a154be8e12f0221fda3c19491101114f8b2.init+0>  000000c4204e2540 
0000700000fbddc0:  000000c420000180  000000c420b58b38 
0000700000fbddd0:  00000000042871a1 <plugin.open+2849>  000000c420000180 
0000700000fbdde0:  0000000000000000  0000000000000000 
0000700000fbddf0:  0000000000000000  0000000000000000 
0000700000fbde00:  0000700000fbde30  00000000044c732c 
0000700000fbde10:  000000c420b58b00  ffffffffffffffff 
0000700000fbde20:  0000000000000125  0000000000000200 
0000700000fbde30:  000000c420b58ab0  000000000405bca0 <runtime.asmcgocall+112> 
0000700000fbde40:  000000c420072180  0000700000fbde68 
0000700000fbde50:  00000000040575b2 <runtime.(*mcache).nextFree.func1+50>  0000000004e00000 
0000700000fbde60:  000000c420b58677  0000000000001580 
0000700000fbde70:  000000c420b58de0  0000000006230649 <runtime.morestack+137> 
0000700000fbde80: <0000000000000000 >0100000004f00000 
runtime.morestack()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:480 +0x89 fp=0x700000fbde88 sp=0x700000fbde80 pc=0x6230649

goroutine 1 [copystack]:
plugin/unnamed-157e9a154be8e12f0221fda3c19491101114f8b2.init()
	<autogenerated>:1 +0x9bd8a fp=0xc4206eab38 sp=0xc4206eab30 pc=0x65409ea
plugin.open(0xc420651d40, 0x56, 0x2, 0xc420651d40, 0x59)
	/usr/local/Cellar/go/1.10/libexec/src/plugin/plugin_dlopen.go:113 +0xb21 fp=0xc4206eadf0 sp=0xc4206eab38 pc=0x42871a1
plugin.Open(0xc420651d40, 0x59, 0x2, 0xc420651d40, 0x59)
	/usr/local/Cellar/go/1.10/libexec/src/plugin/plugin.go:32 +0x35 fp=0xc4206eae28 sp=0xc4206eadf0 pc=0x4286245
neugram.io/ng/gotool.(*Manager).Create(0xc420092a50, 0xc420651c02, 0x17, 0xc4205f6000, 0x3a192, 0x4f719, 0x0, 0x0, 0x0)
	/Users/yves/src/neugram.io/ng/gotool/gotool.go:169 +0x582 fp=0xc4206eaf70 sp=0xc4206eae28 pc=0x4288e52
neugram.io/ng/eval.(*Program).evalStmt(0xc420150100, 0x467bac0, 0xc42014c300, 0x0, 0x0, 0x0)
	/Users/yves/src/neugram.io/ng/eval/eval.go:722 +0x3b07 fp=0xc4206eb850 sp=0xc4206eaf70 pc=0x4472077
neugram.io/ng/eval.(*Program).Eval(0xc420150100, 0x467bac0, 0xc42014c300, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
	/Users/yves/src/neugram.io/ng/eval/eval.go:499 +0x341 fp=0xc4206eb8d8 sp=0xc4206eb850 pc=0x446e351
neugram.io/ng/ngcore.(*Session).Exec(0xc42018e120, 0xc4201cc03c, 0x11, 0xfc4, 0x0, 0x0, 0x0, 0x0, 0x0)
	/Users/yves/src/neugram.io/ng/ngcore/ngcore.go:211 +0x2d1 fp=0xc4206ebca0 sp=0xc4206eb8d8 pc=0x44a17c1
neugram.io/ng/ngcore.(*Session).RunScript(0xc42018e120, 0x4677900, 0xc420158028, 0x0, 0x0, 0xc4201b8000)
	/Users/yves/src/neugram.io/ng/ngcore/ngcore.go:156 +0x12b fp=0xc4206ebdb0 sp=0xc4206ebca0 pc=0x44a126b
main.main()
	/Users/yves/src/neugram.io/ng/ng.go:117 +0x5ce fp=0xc4206ebf88 sp=0xc4206ebdb0 pc=0x44c598e
runtime.main()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:198 +0x212 fp=0xc4206ebfe0 sp=0xc4206ebf88 pc=0x402fae2
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc4206ebfe8 sp=0xc4206ebfe0 pc=0x405cfd1

goroutine 2 [force gc (idle)]:
runtime.gopark(0x460e850, 0x48d2830, 0x45f296e, 0xf, 0x460e714, 0x1)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc42003c768 sp=0xc42003c748 pc=0x402ff3a
runtime.goparkunlock(0x48d2830, 0x45f296e, 0xf, 0x14, 0x1)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:297 +0x5e fp=0xc42003c7a8 sp=0xc42003c768 pc=0x402ffee
runtime.forcegchelper()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:248 +0xcc fp=0xc42003c7e0 sp=0xc42003c7a8 pc=0x402fd7c
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc42003c7e8 sp=0xc42003c7e0 pc=0x405cfd1
created by runtime.init.4
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:237 +0x35

goroutine 3 [GC sweep wait]:
runtime.gopark(0x460e850, 0x48d29a0, 0x45f16be, 0xd, 0x4058114, 0x1)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc42003cf60 sp=0xc42003cf40 pc=0x402ff3a
runtime.goparkunlock(0x48d29a0, 0x45f16be, 0xd, 0x14, 0x1)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:297 +0x5e fp=0xc42003cfa0 sp=0xc42003cf60 pc=0x402ffee
runtime.bgsweep(0xc420070000)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgcsweep.go:71 +0x12c fp=0xc42003cfd8 sp=0xc42003cfa0 pc=0x4020afc
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc42003cfe0 sp=0xc42003cfd8 pc=0x405cfd1
created by runtime.gcenable
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:216 +0x58

goroutine 4 [finalizer wait]:
runtime.gopark(0x460e850, 0x48f0ad8, 0x45f2126, 0xe, 0x14, 0x1)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc42003d718 sp=0xc42003d6f8 pc=0x402ff3a
runtime.goparkunlock(0x48f0ad8, 0x45f2126, 0xe, 0x2000000014, 0x1)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:297 +0x5e fp=0xc42003d758 sp=0xc42003d718 pc=0x402ffee
runtime.runfinq()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mfinal.go:175 +0xad fp=0xc42003d7e0 sp=0xc42003d758 pc=0x4017aad
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc42003d7e8 sp=0xc42003d7e0 pc=0x405cfd1
created by runtime.createfing
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mfinal.go:156 +0x62

goroutine 5 [syscall]:
runtime.notetsleepg(0x48f0e40, 0xffffffffffffffff, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/lock_sema.go:280 +0x4b fp=0xc42003df80 sp=0xc42003df40 pc=0x4011d2b
os/signal.signal_recv(0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/sigqueue.go:139 +0xa7 fp=0xc42003dfa8 sp=0xc42003df80 pc=0x4044a17
os/signal.loop()
	/usr/local/Cellar/go/1.10/libexec/src/os/signal/signal_unix.go:22 +0x22 fp=0xc42003dfe0 sp=0xc42003dfa8 pc=0x40fe392
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc42003dfe8 sp=0xc42003dfe0 pc=0x405cfd1
created by os/signal.init.0
	/usr/local/Cellar/go/1.10/libexec/src/os/signal/signal_unix.go:28 +0x41

goroutine 18 [chan receive]:
runtime.gopark(0x460e850, 0xc4201980b8, 0x45f1137, 0xc, 0xc42002f817, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc42003e698 sp=0xc42003e678 pc=0x402ff3a
runtime.goparkunlock(0xc4201980b8, 0x45f1137, 0xc, 0x17, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:297 +0x5e fp=0xc42003e6d8 sp=0xc42003e698 pc=0x402ffee
runtime.chanrecv(0xc420198060, 0xc42003e7b8, 0x1, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:518 +0x2f2 fp=0xc42003e770 sp=0xc42003e6d8 pc=0x4006372
runtime.chanrecv2(0xc420198060, 0xc42003e7b8, 0x4203d63)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:405 +0x2b fp=0xc42003e7a0 sp=0xc42003e770 pc=0x400606b
neugram.io/ng/eval/shell.Init.func1(0xc420198060)
	/Users/yves/src/neugram.io/ng/eval/shell/job.go:603 +0x47 fp=0xc42003e7d8 sp=0xc42003e7a0 pc=0x414ca57
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc42003e7e0 sp=0xc42003e7d8 pc=0x405cfd1
created by neugram.io/ng/eval/shell.Init
	/Users/yves/src/neugram.io/ng/eval/shell/job.go:602 +0x1d1

goroutine 19 [select, locked to thread]:
runtime.gopark(0x460e898, 0x0, 0x45edde5, 0x6, 0x18, 0x1)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc420038548 sp=0xc420038528 pc=0x402ff3a
runtime.selectgo(0xc420038750, 0xc4201a4120)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/select.go:392 +0xe50 fp=0xc420038720 sp=0xc420038548 pc=0x403f7a0
runtime.ensureSigM.func1()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/signal_unix.go:549 +0x1c6 fp=0xc4200387e0 sp=0xc420038720 pc=0x4059cf6
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc4200387e8 sp=0xc4200387e0 pc=0x405cfd1
created by runtime.ensureSigM
	/usr/local/Cellar/go/1.10/libexec/src/runtime/signal_unix.go:532 +0xda

goroutine 34 [chan receive]:
runtime.gopark(0x460e850, 0xc42013a118, 0x45f1137, 0xc, 0xc42002ae17, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc4201b4698 sp=0xc4201b4678 pc=0x402ff3a
runtime.goparkunlock(0xc42013a118, 0x45f1137, 0xc, 0x17, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:297 +0x5e fp=0xc4201b46d8 sp=0xc4201b4698 pc=0x402ffee
runtime.chanrecv(0xc42013a0c0, 0xc4201b47b8, 0x1, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:518 +0x2f2 fp=0xc4201b4770 sp=0xc4201b46d8 pc=0x4006372
runtime.chanrecv2(0xc42013a0c0, 0xc4201b47b8, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:405 +0x2b fp=0xc4201b47a0 sp=0xc4201b4770 pc=0x400606b
neugram.io/ng/eval/shell.Init.func1(0xc42013a0c0)
	/Users/yves/src/neugram.io/ng/eval/shell/job.go:603 +0x47 fp=0xc4201b47d8 sp=0xc4201b47a0 pc=0x414ca57
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc4201b47e0 sp=0xc4201b47d8 pc=0x405cfd1
created by neugram.io/ng/eval/shell.Init
	/Users/yves/src/neugram.io/ng/eval/shell/job.go:602 +0x1d1

goroutine 35 [chan receive]:
runtime.gopark(0x460e850, 0xc4201c0058, 0x45f1137, 0xc, 0xc420156117, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc42004acc8 sp=0xc42004aca8 pc=0x402ff3a
runtime.goparkunlock(0xc4201c0058, 0x45f1137, 0xc, 0xc42004ae17, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:297 +0x5e fp=0xc42004ad08 sp=0xc42004acc8 pc=0x402ffee
runtime.chanrecv(0xc4201c0000, 0xc42004ae48, 0x429fe01, 0x4e00601)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:518 +0x2f2 fp=0xc42004ada0 sp=0xc42004ad08 pc=0x4006372
runtime.chanrecv1(0xc4201c0000, 0xc42004ae48)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:400 +0x2b fp=0xc42004add0 sp=0xc42004ada0 pc=0x400602b
neugram.io/ng/parser.(*Scanner).next(0xc4201c2000)
	/Users/yves/src/neugram.io/ng/parser/scanner.go:67 +0xaa fp=0xc42004ae70 sp=0xc42004add0 pc=0x429fe4a
neugram.io/ng/parser.(*Scanner).skipWhitespace(0xc4201c2000)
	/Users/yves/src/neugram.io/ng/parser/scanner.go:105 +0x28 fp=0xc42004ae88 sp=0xc42004ae70 pc=0x42a01b8
neugram.io/ng/parser.(*Scanner).Next(0xc4201c2000)
	/Users/yves/src/neugram.io/ng/parser/scanner.go:467 +0x40 fp=0xc42004af38 sp=0xc42004ae88 pc=0x42a1a10
neugram.io/ng/parser.(*Parser).next(0xc4201c4000)
	/Users/yves/src/neugram.io/ng/parser/parser.go:211 +0x2f fp=0xc42004af50 sp=0xc42004af38 pc=0x42914bf
neugram.io/ng/parser.(*Parser).work(0xc4201c4000)
	/Users/yves/src/neugram.io/ng/parser/parser.go:155 +0x88 fp=0xc42004afd8 sp=0xc42004af50 pc=0x4291178
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc42004afe0 sp=0xc42004afd8 pc=0x405cfd1
created by neugram.io/ng/parser.New
	/Users/yves/src/neugram.io/ng/parser/parser.go:30 +0x114

goroutine 20 [chan receive]:
runtime.gopark(0x460e850, 0xc42007c7d8, 0x45f1137, 0xc, 0xc42002ae17, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc420038db0 sp=0xc420038d90 pc=0x402ff3a
runtime.goparkunlock(0xc42007c7d8, 0x45f1137, 0xc, 0x460eb17, 0x3)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:297 +0x5e fp=0xc420038df0 sp=0xc420038db0 pc=0x402ffee
runtime.chanrecv(0xc42007c780, 0xc420038f30, 0x40fe701, 0xc420022790)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:518 +0x2f2 fp=0xc420038e88 sp=0xc420038df0 pc=0x4006372
runtime.chanrecv1(0xc42007c780, 0xc420038f30)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/chan.go:400 +0x2b fp=0xc420038eb8 sp=0xc420038e88 pc=0x400602b
main.initSession.func1()
	/Users/yves/src/neugram.io/ng/ng.go:179 +0xc6 fp=0xc420038fe0 sp=0xc420038eb8 pc=0x44c6586
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc420038fe8 sp=0xc420038fe0 pc=0x405cfd1
created by main.initSession
	/Users/yves/src/neugram.io/ng/ng.go:175 +0xc6

goroutine 22 [GC worker (idle)]:
runtime.gopark(0x460e6d8, 0xc42015e1d0, 0x45f2e22, 0x10, 0xc420198014, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc4201b4f48 sp=0xc4201b4f28 pc=0x402ff3a
runtime.gcBgMarkWorker(0xc42002a000)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1775 +0x130 fp=0xc4201b4fd8 sp=0xc4201b4f48 pc=0x401b710
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc4201b4fe0 sp=0xc4201b4fd8 pc=0x405cfd1
created by runtime.gcBgMarkStartWorkers
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1723 +0x79

goroutine 23 [GC worker (idle)]:
runtime.gopark(0x460e6d8, 0xc42015e1e0, 0x45f2e22, 0x10, 0x14, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc420039748 sp=0xc420039728 pc=0x402ff3a
runtime.gcBgMarkWorker(0xc42002c500)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1775 +0x130 fp=0xc4200397d8 sp=0xc420039748 pc=0x401b710
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc4200397e0 sp=0xc4200397d8 pc=0x405cfd1
created by runtime.gcBgMarkStartWorkers
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1723 +0x79

goroutine 24 [GC worker (idle)]:
runtime.gopark(0x460e6d8, 0xc42015e1f0, 0x45f2e22, 0x10, 0x14, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc420039f48 sp=0xc420039f28 pc=0x402ff3a
runtime.gcBgMarkWorker(0xc42002ea00)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1775 +0x130 fp=0xc420039fd8 sp=0xc420039f48 pc=0x401b710
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc420039fe0 sp=0xc420039fd8 pc=0x405cfd1
created by runtime.gcBgMarkStartWorkers
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1723 +0x79

goroutine 7 [GC worker (idle)]:
runtime.gopark(0x460e6d8, 0xc4200227a0, 0x45f2e22, 0x10, 0x14, 0x0)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/proc.go:291 +0x11a fp=0xc42003ef48 sp=0xc42003ef28 pc=0x402ff3a
runtime.gcBgMarkWorker(0xc420030f00)
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1775 +0x130 fp=0xc42003efd8 sp=0xc42003ef48 pc=0x401b710
runtime.goexit()
	/usr/local/Cellar/go/1.10/libexec/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc42003efe0 sp=0xc42003efd8 pc=0x405cfd1
created by runtime.gcBgMarkStartWorkers
	/usr/local/Cellar/go/1.10/libexec/src/runtime/mgc.go:1723 +0x79