Loading "lparallel" hangs

Hello,

can you provide me some hints for the following problem ?

I've compiled ecl from git on a debian stretch machine. Then I've tried to compile the "qt" example, which did hang when loading "lparallel" So I started "ecl" from a shell, and did execute (ql:quickload :lparallel) which presents me:

To load "lparallel": Load 1 ASDF system: lparallel ; Loading "lparallel"

then the process fell silent. "top" doesn't show "ecl" to consume cpu cycles. Its waiting for something and doesn't proceed.

Regards, Robert Larice