It looks like this is known issue and Core team knows about it. So, waiting for the solution...
- [julia-users] Memory leak in Task and fatal error Ded Don
- [julia-users] Re: Memory leak in Task and fatal error DeadbraiN
- [julia-users] Re: Memory leak in Task and fatal error DeadbraiN
- [julia-users] Re: Memory leak in Task and fatal error DeadbraiN