Can't redirect segmentation fault error to file

[Ismail Donmez <ismail@xxxxxxxx>]

Hi,

Suppose I have a crashing executable:

λ ./a.out            
[1]    6511 segmentation fault (core dumped)  ./a.out


For some reason I want to redirect the segmentation fault error to a file.

λ { ./a.out; } 2> err
λ 

I do that and err is an empty file. Same thing seems to work fine in bash. I 
tried with zsh 5.1.1 without success.