Creator crashes with std::bad_alloc

Compiled recent Qt 4.7
Compiled head creator (including qttest plugin)
Enabled Qttest plugin in 'About plugins'
Launch Creator
split left hand plane and make sure 'Tests' are shown in one of them.
open Qt/master project

Problem:
QtCreator(6940)/ KSycocaPrivate::openDatabase: Trying to open ksycoca from "/var/tmp/kdecache-ebaak/ksycoca4"
Qt Concurrent has caught an exception thrown from a worker thread.
This is not supported, exceptions thrown in worker threads must be
caught before control returns to Qt Concurrent.
terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc
Aborted