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

runtime stack:
runtime.SetFinalizer.func2()
        /home/derek/go/src/github.com/golang/go/src/runtime/mfinal.go:375 +0x73

goroutine 3032331 [running]:
runtime.systemstack_switch()
        /home/derek/go/src/github.com/golang/go/src/runtime/asm_amd64.s:252 fp=0xc42049f3b8 sp=0xc42049f3b0
runtime.SetFinalizer(0x4a5680, 0xc42000e580, 0x4a4980, 0x4c86b0)
        /home/derek/go/src/github.com/golang/go/src/runtime/mfinal.go:377 +0x250 fp=0xc42049f498 sp=0xc42049f3b8
os.NewFile(0xd, 0x4be30a, 0x9, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/file_unix.go:57 +0xe4 fp=0xc42049f4d0 sp=0xc42049f498
os.OpenFile(0x4be30a, 0x9, 0x1, 0xc400000000, 0x1, 0x800519960, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/file_unix.go:123 +0xf2 fp=0xc42049f538 sp=0xc42049f4d0
os/exec.(*Cmd).writerDescriptor(0xc4202fa140, 0x0, 0x0, 0x0, 0x0, 0xc420438050)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:217 +0x539 fp=0xc42049f5d8 sp=0xc42049f538
os/exec.(*Cmd).stderr(0xc4202fa140, 0xc420438048, 0x1, 0x1)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:212 +0x44 fp=0xc42049f620 sp=0xc42049f5d8
os/exec.(*Cmd).Start(0xc4202fa140, 0x4, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:326 +0xd6 fp=0xc42049f768 sp=0xc42049f620
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:39 +0x5e fp=0xc42049f7b8 sp=0xc42049f768
runtime.goexit()
        /home/derek/go/src/github.com/golang/go/src/runtime/asm_amd64.s:2058 +0x1 fp=0xc42049f7c0 sp=0xc42049f7b8
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3

goroutine 1 [runnable]:
main.main()
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:62 +0x181

goroutine 3032406 [runnable]:
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:37
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3

goroutine 3032357 [runnable]:
os/exec.(*Cmd).writerDescriptor(0xc42030a140, 0x0, 0x0, 0x0, 0x0, 0x1)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:221 +0x624
os/exec.(*Cmd).stdout(0xc42030a140, 0x0, 0x0, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:205 +0x33
os/exec.(*Cmd).Start(0xc42030a140, 0x4, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:326 +0xd6
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:39 +0x5e
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3

goroutine 3032405 [runnable]:
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:37
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3

goroutine 3032389 [runnable]:
syscall.Syscall(0x3, 0x5, 0xc4203a3bd8, 0x8, 0x0, 0x8, 0x0)
        /home/derek/go/src/github.com/golang/go/src/syscall/asm_freebsd_amd64.s:21 +0x5
syscall.readlen(0x5, 0xc4203a3bd8, 0x8, 0x2, 0xc4202421b0, 0x12)
        /home/derek/go/src/github.com/golang/go/src/syscall/zsyscall_freebsd_amd64.go:1302 +0x4c
syscall.forkExec(0xc420304230, 0xd, 0xc420304180, 0x1, 0x1, 0xc4203a3d70, 0xc4200c2000, 0x4c7764, 0x47ee50)
        /home/derek/go/src/github.com/golang/go/src/syscall/exec_unix.go:202 +0x38f
syscall.StartProcess(0xc420304230, 0xd, 0xc420304180, 0x1, 0x1, 0xc4203a3d70, 0x2, 0x4, 0xc420117ba0, 0x0)
        /home/derek/go/src/github.com/golang/go/src/syscall/exec_unix.go:240 +0x53
os.startProcess(0xc420304230, 0xd, 0xc420304180, 0x1, 0x1, 0xc4203a3f08, 0xc4204da120, 0x11, 0x11)
        /home/derek/go/src/github.com/golang/go/src/os/exec_posix.go:45 +0x186
os.StartProcess(0xc420304230, 0xd, 0xc420304180, 0x1, 0x1, 0xc4203a3f08, 0x0, 0x0, 0xc420304230)
        /home/derek/go/src/github.com/golang/go/src/os/doc.go:28 +0x53
os/exec.(*Cmd).Start(0xc420310000, 0x4, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:342 +0x393
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:39 +0x5e
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3

goroutine 3032345 [runnable]:
sync.(*RWMutex).RUnlock(0x544ed0)
        /home/derek/go/src/github.com/golang/go/src/sync/rwmutex.go:51
syscall.Environ(0xc4204ea120, 0x11, 0x11)
        /home/derek/go/src/github.com/golang/go/src/syscall/env_unix.go:148 +0x1fb
os.Environ(0x0, 0x0, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/env.go:116 +0x18
os/exec.(*Cmd).envv(0xc4202ee140, 0xc4203202d8, 0x0, 0x1)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:155 +0x2e
os/exec.(*Cmd).Start(0xc4202ee140, 0x4, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:340 +0x2b1
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:39 +0x5e
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3

goroutine 3032404 [runnable]:
syscall.Syscall(0x6, 0x9, 0x0, 0x0, 0x0, 0x0, 0x0)
        /home/derek/go/src/github.com/golang/go/src/syscall/asm_freebsd_amd64.s:21 +0x5
syscall.Close(0x9, 0xc42013fbd8, 0x8)
        /home/derek/go/src/github.com/golang/go/src/syscall/zsyscall_freebsd_amd64.go:384 +0x40
syscall.forkExec(0xc42031e270, 0xd, 0xc42031e1c0, 0x1, 0x1, 0xc42013fd70, 0xc420052400, 0x4c7764, 0x80051ac20)
        /home/derek/go/src/github.com/golang/go/src/syscall/exec_unix.go:203 +0x3c4
syscall.StartProcess(0xc42031e270, 0xd, 0xc42031e1c0, 0x1, 0x1, 0xc42013fd70, 0x2, 0x4, 0xc420091ba0, 0x0)
        /home/derek/go/src/github.com/golang/go/src/syscall/exec_unix.go:240 +0x53
os.startProcess(0xc42031e270, 0xd, 0xc42031e1c0, 0x1, 0x1, 0xc42013ff08, 0xc4204ee120, 0x11, 0x11)
        /home/derek/go/src/github.com/golang/go/src/os/exec_posix.go:45 +0x186
os.StartProcess(0xc42031e270, 0xd, 0xc42031e1c0, 0x1, 0x1, 0xc42013ff08, 0x0, 0x0, 0xc42031e270)
        /home/derek/go/src/github.com/golang/go/src/os/doc.go:28 +0x53
os/exec.(*Cmd).Start(0xc4202ea140, 0x4, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:342 +0x393
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:39 +0x5e
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3

goroutine 3032374 [runnable]:
path/filepath.Join(0xc4204a06d0, 0x2, 0x2, 0xa, 0xa)
        /home/derek/go/src/github.com/golang/go/src/path/filepath/path.go:205
os/exec.LookPath(0x4bdb4d, 0x4, 0x4bdb4d, 0x4, 0x1, 0x0)
        /home/derek/go/src/github.com/golang/go/src/os/exec/lp_unix.go:52 +0x156
os/exec.Command(0x4bdb4d, 0x4, 0x0, 0x0, 0x0, 0xc42022b400)
        /home/derek/go/src/github.com/golang/go/src/os/exec/exec.go:133 +0x1d1
main.run(0xc42006e060)
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:38 +0x4b
created by main.main
        /home/derek/dev/crashgo/src/cmd/crashgo/main.go:63 +0x1a3