Starting a bunch of goroutines...
fatal error: runtime.SetFinalizer: finalizer already set

runtime stack:
runtime.throw(0x544ce0, 0x2b)
	/usr/local/go/src/runtime/panic.go:547 +0x90 fp=0xc8200d7f48 sp=0xc8200d7f30
runtime.SetFinalizer.func2()
	/usr/local/go/src/runtime/mfinal.go:372 +0x6f fp=0xc8200d7f80 sp=0xc8200d7f48
runtime.systemstack(0xc82001aa00)
	/usr/local/go/src/runtime/asm_amd64.s:291 +0x79 fp=0xc8200d7f88 sp=0xc8200d7f80
runtime.mstart()
	/usr/local/go/src/runtime/proc.go:1051 fp=0xc8200d7f90 sp=0xc8200d7f88

goroutine 139647 [running]:
runtime.systemstack_switch()
	/usr/local/go/src/runtime/asm_amd64.s:245 fp=0xc820121a48 sp=0xc820121a40
runtime.SetFinalizer(0x4f2f60, 0xc82038be60, 0x4d6900, 0x54f5d0)
	/usr/local/go/src/runtime/mfinal.go:374 +0x4b5 fp=0xc820121bc8 sp=0xc820121a48
os.NewFile(0x10, 0x51f040, 0x9, 0xc800000000)
	/usr/local/go/src/os/file_unix.go:57 +0xfc fp=0xc820121c20 sp=0xc820121bc8
os.OpenFile(0x51f040, 0x9, 0x0, 0x0, 0xecbf470a7, 0x0, 0x0)
	/usr/local/go/src/os/file_unix.go:123 +0x1bd fp=0xc820121c98 sp=0xc820121c20
os.Open(0x51f040, 0x9, 0x47e47f, 0x0, 0x0)
	/usr/local/go/src/os/file.go:244 +0x48 fp=0xc820121cd8 sp=0xc820121c98
os/exec.(*Cmd).stdin(0xc82013aa00, 0x0, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:171 +0x6e fp=0xc820121d70 sp=0xc820121cd8
os/exec.(*Cmd).Start(0xc82013aa00, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:316 +0x2f4 fp=0xc820121f58 sp=0xc820121d70
main.run(0xc820028028)
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:43 +0x54 fp=0xc820121fa8 sp=0xc820121f58
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc820121fb0 sp=0xc820121fa8
created by main.main
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:66 +0x1c1

goroutine 1 [runnable]:
runtime.gopark(0x54f910, 0xc8200580b8, 0x520cb0, 0xc, 0x17, 0x3)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc82017ddf0 sp=0xc82017ddc8
runtime.goparkunlock(0xc8200580b8, 0x520cb0, 0xc, 0x17, 0x3)
	/usr/local/go/src/runtime/proc.go:268 +0x54 fp=0xc82017de28 sp=0xc82017ddf0
runtime.chanrecv(0x4ca720, 0xc820058060, 0x0, 0xc82017de01, 0x400000)
	/usr/local/go/src/runtime/chan.go:470 +0x49f fp=0xc82017deb0 sp=0xc82017de28
runtime.chanrecv1(0x4ca720, 0xc820058060, 0x0)
	/usr/local/go/src/runtime/chan.go:355 +0x2b fp=0xc82017dee0 sp=0xc82017deb0
main.main()
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:65 +0x19f fp=0xc82017df70 sp=0xc82017dee0
runtime.main()
	/usr/local/go/src/runtime/proc.go:188 +0x2b0 fp=0xc82017dfc0 sp=0xc82017df70
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc82017dfc8 sp=0xc82017dfc0

goroutine 2 [force gc (idle), 2 minutes]:
runtime.gopark(0x54f910, 0x5bf790, 0x5213c0, 0xf, 0x14, 0x1)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc820024758 sp=0xc820024730
runtime.goparkunlock(0x5bf790, 0x5213c0, 0xf, 0xc820000114, 0x1)
	/usr/local/go/src/runtime/proc.go:268 +0x54 fp=0xc820024790 sp=0xc820024758
runtime.forcegchelper()
	/usr/local/go/src/runtime/proc.go:229 +0xb8 fp=0xc8200247c0 sp=0xc820024790
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8200247c8 sp=0xc8200247c0
created by runtime.init.4
	/usr/local/go/src/runtime/proc.go:218 +0x2b

goroutine 3 [GC sweep wait]:
runtime.gopark(0x54f910, 0x5bf8a0, 0x51f500, 0xd, 0x449614, 0x1)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc820024f48 sp=0xc820024f20
runtime.goparkunlock(0x5bf8a0, 0x51f500, 0xd, 0x14, 0x1)
	/usr/local/go/src/runtime/proc.go:268 +0x54 fp=0xc820024f80 sp=0xc820024f48
runtime.bgsweep(0xc820056000)
	/usr/local/go/src/runtime/mgcsweep.go:79 +0x14d fp=0xc820024fb8 sp=0xc820024f80
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc820024fc0 sp=0xc820024fb8
created by runtime.gcenable
	/usr/local/go/src/runtime/mgc.go:191 +0x53

goroutine 4 [finalizer wait]:
runtime.gopark(0x54f910, 0x5d9e28, 0x521110, 0xe, 0x100000014, 0x1)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc820025718 sp=0xc8200256f0
runtime.goparkunlock(0x5d9e28, 0x521110, 0xe, 0x2000000014, 0x1)
	/usr/local/go/src/runtime/proc.go:268 +0x54 fp=0xc820025750 sp=0xc820025718
runtime.runfinq()
	/usr/local/go/src/runtime/mfinal.go:158 +0xaa fp=0xc8200257c0 sp=0xc820025750
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8200257c8 sp=0xc8200257c0
created by runtime.createfing
	/usr/local/go/src/runtime/mfinal.go:139 +0x60

goroutine 139695 [runnable]:
runtime.newarray(0x4d0d00, 0xa, 0x40e205)
	/usr/local/go/src/runtime/malloc.go:790 fp=0xc8200212b8 sp=0xc8200212b0
runtime.makeslice(0x4ca3c0, 0xa, 0xa, 0x0, 0x0, 0x0)
	/usr/local/go/src/runtime/slice.go:32 +0x165 fp=0xc820021308 sp=0xc8200212b8
syscall.ByteSliceFromString(0x51f040, 0x9, 0x0, 0x0, 0x0, 0x0, 0x0)
	/usr/local/go/src/syscall/syscall.go:53 +0x126 fp=0xc820021390 sp=0xc820021308
syscall.BytePtrFromString(0x51f040, 0x9, 0xc8201f1bb0, 0x0, 0x0)
	/usr/local/go/src/syscall/syscall.go:69 +0x3b fp=0xc8200213d0 sp=0xc820021390
syscall.Open(0x51f040, 0x9, 0x100000, 0xc800000000, 0x0, 0x0, 0x0)
	/usr/local/go/src/syscall/zsyscall_freebsd_amd64.go:819 +0x4f fp=0xc820021430 sp=0xc8200213d0
os.OpenFile(0x51f040, 0x9, 0x0, 0x0, 0xecbf470a7, 0x0, 0x0)
	/usr/local/go/src/os/file_unix.go:97 +0x12c fp=0xc8200214a8 sp=0xc820021430
os.Open(0x51f040, 0x9, 0x47e47f, 0x0, 0x0)
	/usr/local/go/src/os/file.go:244 +0x48 fp=0xc8200214e8 sp=0xc8200214a8
os/exec.(*Cmd).stdin(0xc82038ec80, 0x0, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:171 +0x6e fp=0xc820021580 sp=0xc8200214e8
os/exec.(*Cmd).Start(0xc82038ec80, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:316 +0x2f4 fp=0xc820021768 sp=0xc820021580
main.run(0xc820028028)
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:43 +0x54 fp=0xc8200217b8 sp=0xc820021768
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8200217c0 sp=0xc8200217b8
created by main.main
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:66 +0x1c1

goroutine 1082 [GC worker (idle)]:
runtime.gopark(0xc820454e18, 0xc82019d7a0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc82019d740 sp=0xc82019d718
runtime.gcBgMarkWorker(0xc82001d500)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc82019d7b8 sp=0xc82019d740
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc82019d7c0 sp=0xc82019d7b8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 1080 [GC worker (idle)]:
runtime.gopark(0xc8204456c8, 0xc820027fa0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc820027f40 sp=0xc820027f18
runtime.gcBgMarkWorker(0xc82001aa00)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc820027fb8 sp=0xc820027f40
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc820027fc0 sp=0xc820027fb8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 1107 [GC worker (idle)]:
runtime.gopark(0xc820459408, 0xc8203e9fa0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc8203e9f40 sp=0xc8203e9f18
runtime.gcBgMarkWorker(0xc820015500)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc8203e9fb8 sp=0xc8203e9f40
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8203e9fc0 sp=0xc8203e9fb8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 1081 [GC worker (idle)]:
runtime.gopark(0xc820257fb8, 0xc8201a27a0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc8201a2740 sp=0xc8201a2718
runtime.gcBgMarkWorker(0xc82001c000)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc8201a27b8 sp=0xc8201a2740
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8201a27c0 sp=0xc8201a27b8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 139676 [runnable]:
sync.(*Mutex).Unlock(0x5d9f60)
	/usr/local/go/src/sync/mutex.go:100 fp=0xc8201a8a30 sp=0xc8201a8a28
sync.(*RWMutex).Unlock(0x5d9f60)
	/usr/local/go/src/sync/rwmutex.go:122 +0xfc fp=0xc8201a8a80 sp=0xc8201a8a30
syscall.forkExec(0xc82026c620, 0xd, 0xc82026c5b0, 0x1, 0x1, 0xc8201a8cd0, 0x42b2, 0x0, 0x0)
	/usr/local/go/src/syscall/exec_unix.go:198 +0x592 fp=0xc8201a8ba0 sp=0xc8201a8a80
syscall.StartProcess(0xc82026c620, 0xd, 0xc82026c5b0, 0x1, 0x1, 0xc8201a8cd0, 0x2, 0x4, 0x0, 0x0)
	/usr/local/go/src/syscall/exec_unix.go:240 +0x6b fp=0xc8201a8bf0 sp=0xc8201a8ba0
os.startProcess(0xc82026c620, 0xd, 0xc82026c5b0, 0x1, 0x1, 0xc8201a8f08, 0xc8204007e0, 0x0, 0x0)
	/usr/local/go/src/os/exec_posix.go:45 +0x33e fp=0xc8201a8d20 sp=0xc8201a8bf0
os.StartProcess(0xc82026c620, 0xd, 0xc82026c5b0, 0x1, 0x1, 0xc8201a8f08, 0x0, 0x0, 0x0)
	/usr/local/go/src/os/doc.go:28 +0x69 fp=0xc8201a8d70 sp=0xc8201a8d20
os/exec.(*Cmd).Start(0xc8202d7400, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:332 +0x761 fp=0xc8201a8f58 sp=0xc8201a8d70
main.run(0xc820028028)
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:43 +0x54 fp=0xc8201a8fa8 sp=0xc8201a8f58
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8201a8fb0 sp=0xc8201a8fa8
created by main.main
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:66 +0x1c1

goroutine 1106 [GC worker (idle)]:
runtime.gopark(0xc8202f5910, 0xc820181fa0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc820181f40 sp=0xc820181f18
runtime.gcBgMarkWorker(0xc820014000)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc820181fb8 sp=0xc820181f40
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc820181fc0 sp=0xc820181fb8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 1018 [GC worker (idle)]:
runtime.gopark(0xc820311e60, 0xc8202c5fa0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc8202c5f40 sp=0xc8202c5f18
runtime.gcBgMarkWorker(0xc820016a00)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc8202c5fb8 sp=0xc8202c5f40
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8202c5fc0 sp=0xc8202c5fb8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 1019 [GC worker (idle)]:
runtime.gopark(0xc8200e8910, 0xc82017f7a0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc82017f740 sp=0xc82017f718
runtime.gcBgMarkWorker(0xc820018000)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc82017f7b8 sp=0xc82017f740
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc82017f7c0 sp=0xc82017f7b8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 1020 [GC worker (idle)]:
runtime.gopark(0xc8203bf868, 0xc8201a1fa0, 0x532830, 0x10, 0x401014, 0x0)
	/usr/local/go/src/runtime/proc.go:262 +0x163 fp=0xc8201a1f40 sp=0xc8201a1f18
runtime.gcBgMarkWorker(0xc820019500)
	/usr/local/go/src/runtime/mgc.go:1403 +0xda fp=0xc8201a1fb8 sp=0xc8201a1f40
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8201a1fc0 sp=0xc8201a1fb8
created by runtime.gcBgMarkStartWorkers
	/usr/local/go/src/runtime/mgc.go:1330 +0x92

goroutine 139749 [runnable]:
runtime.growslice(0x4c8680, 0x0, 0x0, 0x0, 0x1, 0x46c380, 0xc8202396e0, 0xd)
	/usr/local/go/src/runtime/slice.go:51 fp=0xc82011cd70 sp=0xc82011cd68
os/exec.(*Cmd).Start(0xc82020af00, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:322 +0xafb fp=0xc82011cf58 sp=0xc82011cd70
main.run(0xc820028028)
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:43 +0x54 fp=0xc82011cfa8 sp=0xc82011cf58
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc82011cfb0 sp=0xc82011cfa8
created by main.main
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:66 +0x1c1

goroutine 139764 [runnable]:
runtime.growslice(0x4c9280, 0x0, 0x0, 0x0, 0x1, 0xd, 0x0, 0x0)
	/usr/local/go/src/runtime/slice.go:51 fp=0xc8201aecd8 sp=0xc8201aecd0
os/exec.(*Cmd).stdin(0xc820349cc0, 0xc82015e8e0, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:175 +0x16b fp=0xc8201aed70 sp=0xc8201aecd8
os/exec.(*Cmd).Start(0xc820349cc0, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:316 +0x2f4 fp=0xc8201aef58 sp=0xc8201aed70
main.run(0xc820028028)
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:43 +0x54 fp=0xc8201aefa8 sp=0xc8201aef58
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8201aefb0 sp=0xc8201aefa8
created by main.main
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:66 +0x1c1

goroutine 139763 [runnable]:
os/exec.(*Cmd).Wait(0xc820349b80, 0x0, 0x0)
	/usr/local/go/src/os/exec/exec.go:388 fp=0xc820389f58 sp=0xc820389f50
main.run(0xc820028028)
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:50 +0xaa fp=0xc820389fa8 sp=0xc820389f58
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc820389fb0 sp=0xc820389fa8
created by main.main
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:66 +0x1c1

goroutine 139709 [runnable]:
syscall.Syscall(0xbc, 0xc82006d9a0, 0xc8204809d8, 0x0, 0xffffffffffffffff, 0x0, 0x2)
	/usr/local/go/src/syscall/asm_freebsd_amd64.s:21 +0x5 fp=0xc82019fca0 sp=0xc82019fc98
syscall.Stat(0xc82006d990, 0xa, 0xc8204809d8, 0x0, 0x0)
	/usr/local/go/src/syscall/zsyscall_freebsd_amd64.go:1133 +0x9e fp=0xc82019fd00 sp=0xc82019fca0
os.Stat(0xc82006d990, 0xa, 0x0, 0x0, 0x0, 0x0)
	/usr/local/go/src/os/file_unix.go:169 +0x6f fp=0xc82019fd58 sp=0xc82019fd00
os/exec.findExecutable(0xc82006d990, 0xa, 0x0, 0x0)
	/usr/local/go/src/os/exec/lp_unix.go:19 +0x3b fp=0xc82019fdb0 sp=0xc82019fd58
os/exec.LookPath(0x51df38, 0x4, 0x0, 0x0, 0x0, 0x0)
	/usr/local/go/src/os/exec/lp_unix.go:55 +0x470 fp=0xc82019feb0 sp=0xc82019fdb0
os/exec.Command(0x51df38, 0x4, 0x0, 0x0, 0x0, 0xc8202bea00)
	/usr/local/go/src/os/exec/exec.go:132 +0x2f3 fp=0xc82019ff68 sp=0xc82019feb0
main.run(0xc820028028)
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:42 +0x41 fp=0xc82019ffb8 sp=0xc82019ff68
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc82019ffc0 sp=0xc82019ffb8
created by main.main
	/home/derek/dev/crashgo/src/cmd/crashgo/main.go:66 +0x1c1