qtcreator segfaults on loading qml files

When creating a new project with a qml file, say:

  > New Project > Application > Qt Quick Application - Empty

qtcreator segfaults as soon as the Editor component is visible.

Process 27930 stopped

• thread #9, name = 'qtcreator', stop reason = signal SIGSEGV: invalid address (fault address: 0x8470b5750)
      frame #0: 0x000000081a4e254f libQmlJS.so.4`QmlJS::Context::imports(QmlJS::Document const*) const + 63
  libQmlJS.so.4`QmlJS::Context::imports:
  ->  0x81a4e254f <+63>: movq   (%r8,%rdx,8), %rax
      0x81a4e2553 <+67>: xorl   %ebx, %ebx
      0x81a4e2555 <+69>: cmpq   %rdi, %rax
      0x81a4e2558 <+72>: je     0x81a4e25b4               ; <+164>

• thread #9, name = 'qtcreator', stop reason = signal SIGSEGV: invalid address (fault address: 0x8470b5750)
    * frame #0: 0x000000081a4e254f libQmlJS.so.4`QmlJS::Context::imports(QmlJS::Document const*) const + 63
      frame #1: 0x000000081a4e25f0 libQmlJS.so.4`QmlJS::Context::lookupType(QmlJS::Document const*, QmlJS::AST::UiQualifiedId*, QmlJS::AST::UiQualifiedId) const + 32
      frame #2: 0x000000081a4e2b6f libQmlJS.so.4`QmlJS::Context::lookupReference(QmlJS::Value const*) const + 239
      frame #3: 0x000000081a47406b libQmlJS.so.4`QmlJS::PrototypeIterator::hasNext(void) + 171
      frame #4: 0x000000081a49a3f8 libQmlJS.so.4`QmlJS::ScopeBuilder::setQmlScopeObject(QmlJS::AST::Node*) + 408
      frame #5: 0x000000081a499de1 libQmlJS.so.4`QmlJS::ScopeBuilder::push(QmlJS::AST::Node*) + 161
      frame #6: 0x000000081a48b46e libQmlJS.so.4`QmlJS::Check::visitQmlObject(QmlJS::AST::Node*, QmlJS::Check::visitQmlObject::UiQualifiedId*, QmlJS::Check::visitQmlObject::UiObjectInitializer*) + 3838
      frame #7: 0x000000081a48a561 libQmlJS.so.4`QmlJS::Check::visit(QmlJS::AST::UiObjectDefinition*) + 17
      frame #8: 0x000000081a43252c libQmlJS.so.4`QmlJS::AST::UiObjectDefinition::accept0(QmlJS::AST::Visitor*) + 28
      frame #9: 0x000000081a4328c6 libQmlJS.so.4`QmlJS::AST::UiObjectMemberList::accept0(QmlJS::AST::Visitor*) + 86
      frame #10: 0x000000081a432446 libQmlJS.so.4`QmlJS::AST::UiProgram::accept0(QmlJS::AST::Visitor*) + 118
      frame #11: 0x000000081a42fc3e libQmlJS.so.4`QmlJS::AST::Node::accept(QmlJS::AST::Node*, QmlJS::AST::Visitor*) + 46
      frame #12: 0x000000081a489035 libQmlJS.so.4`QmlJS::Check::operator()(void) + 101
      frame #13: 0x000000082f1cebaf libQmlJSEditor.so`___lldb_unnamed_symbol1040$$libQmlJSEditor.so + 1279
      frame #14: 0x000000082f1ce551 libQmlJSEditor.so`___lldb_unnamed_symbol1039$$libQmlJSEditor.so + 417
      frame #15: 0x00000008028ae70a libQt5Core.so.5`___lldb_unnamed_symbol263$$libQt5Core.so.5 + 234
      frame #16: 0x0000000801848426 libthr.so.3`thread_start(curthread=0x000000083f55fa00) at thr_create.c:291

There is a downstream bug report for the issue too.