Hangs on toStringZ()

[Marc Schütz via Digitalmars-d]

On Tuesday, 27 December 2016 at 17:27:14 UTC, unDEFER wrote:
> Hello I have very simple line with exec-command:
>
> execl("/bin/bash".toStringz(), "/bin/bash".toStringz(), 
> "-c".toStringz(), command.toStringz(), null);
>
> And on this line on toStringz my program sometimes hangs.
> backtrace:
>
> (gdb) bt
> #0  0x00007f3acd535c6d in nanosleep () at 
> ../sysdeps/unix/syscall-template.S:84
> #1  0x000000000066f57e in 
> core.thread.Thread.sleep(core.time.Duration) ()
> #2  0x00000000006b2824 in 
> core.internal.spinlock.SpinLock.yield(ulong) shared
>     ()
> #3  0x00000000006b27c0 in 
> core.internal.spinlock.SpinLock.lock() shared ()
> #4  0x00000000006a7244 in 
> gc.gc.GC.runLocked!(gc.gc.GC.mallocNoSync(ulong, uint, ref 
> ulong, const(TypeInfo)), gc.gc.mallocTime, gc.gc.numMallocs, 
> ulong, uint, ulong, const(TypeInfo)).runLocked(ref ulong, ref 
> uint, ref ulong, ref const(TypeInfo)) ()
> #5  0x00000000006a0bc6 in gc.gc.GC.malloc(ulong, uint, ulong*, 
> const(TypeInfo))
>     ()
> #6  0x00000000006721d3 in gc_qalloc ()
> #7  0x00000000006a99a1 in rt.lifetime.__arrayAlloc(ulong, 
> const(TypeInfo), const(TypeInfo)) ()
> #8  0x000000000067523a in _d_newarrayU ()
> #9  0x0000000000675324 in _d_newarrayiT ()
> #10 0x000000000068fde6 in std.string.toStringz(const(char)[]) ()
> #11 0x000000000068fe79 in 
> std.string.toStringz(const(immutable(char)[])) ()
> #12 0x0000000000592dc9 in 
> unde.command_line.run.fork_command(unde.global_state.CMDGlobalState, immutable(char)[], immutable(char)[], std.concurrency.Tid) (
>     tid=..., command=..., cwd=..., cgs=0x7f3abcdffb80)
>     at source/unde/command_line/run.d:2002
>
> What is it? For what it waits?

What context are you calling this from? Is this in a signal 
handler? Or from inside a destructor of a GC-owned object?