Some systems failed to build for Quicklisp dist

[quicklisp]

Building with SBCL 2.1.7.62-417920f09 / ASDF 3.3.5 for quicklisp dist creation.

Trying to build commit id fe96152

weblocks-demo-popover fails to build because of a failure in weblocks.

weblocks-s11 fails to build because of a failure in weblocks.

weblocks-test fails to build because of a failure in weblocks.

weblocks-yarek fails to build because of a failure in weblocks.

weblocks-yui fails to build because of a failure in weblocks.

weblocks fails to build with the following error:

; caught WARNING:
;   Derived type of #:G8 is (MEMBER CHILDREN), conflicting with its asserted type LIST.
;   See also:
;     The SBCL Manual, Node "Handling of Types"
...
Unhandled UIOP/LISP-BUILD:COMPILE-FILE-ERROR in thread #<SB-THREAD:THREAD "main thread" RUNNING {1001BF0103}>: COMPILE-FILE-ERROR while compiling #<CL-SOURCE-FILE "weblocks" "src" "widgets" "widget" "widget">

Full log here