zlib performance

[yawniek via Digitalmars-d-learn]

On Friday, 7 August 2015 at 07:29:15 UTC, Daniel Kozák wrote:
> Which compiler and version. There has been some performance 
> problem with IO on OSX, it should be fixed in 2.068 release

i'm on master. v2.068-devel-8f81ffc
also changed file read mode to "rb".

i don't understand why the program crashes when i do not do the 
.dup