Trust session cannot be created on Unity8 desktop session

Debug output from online-account-service

signonui-service.cpp 227 queryDialog Got request: QMap(("AppId", QVariant(QString, ""))("Caption", QVariant(QString, ""))("ClientData", QVariant(QVariantMap, QMap()))("Identity", QVariant(uint, 6))("Mechanism", QVariant(QString, "password"))("Method", QVariant(QString, "password"))("Pid", QVariant(int, 1185))("QueryPassword", QVariant(bool, true))("QueryUserName", QVariant(bool, true))("StoredIdentity", QVariant(bool, true))("requestId", QVariant(QString, "/com/google/code/AccountsSSO/SingleSignOn/AuthSession_0")))
utils.cpp 49 apparmorProfileOfPeer App ID: "unconfined"
request-manager.cpp 113 runQueue Head: OnlineAccountsUi::Request(0x11a5490)
Invalid prompt session: Error processing request: Could not identify application session
Internal error details: /build/mir-YefCL3/mir-0.23.3+16.04.20160707.1/src/server/scene/prompt_session_manager_impl.cpp(137): Throw in function virtual std::shared_ptr<mir::scene::PromptSession> mir::scene::PromptSessionManagerImpl::start_prompt_session_for(const std::shared_ptr<mir::scene::Session>&, const mir::scene::PromptSessionCreationParameters&) const
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::runtime_error> >
std::exception::what: Could not identify application session

Couldn't setup prompt session
UiProxy initialization failed!ignonui-service.cpp 227 queryDialog Got request: QMap(("AppId", QVariant(QString, ""))("Caption", QVariant(QString, ""))("ClientData", QVariant(QVariantMap, QMap()))("Identity", QVariant(uint, 6))("Mechanism", QVariant(QString, "password"))("Method", QVariant(QString, "password"))("Pid", QVariant(int, 1185))("QueryPassword", QVariant(bool, true))("QueryUserName", QVariant(bool, true))("StoredIdentity", QVariant(bool, true))("requestId", QVariant(QString, "/com/google/code/AccountsSSO/SingleSignOn/AuthSession_0")))
utils.cpp 49 apparmorProfileOfPeer App ID: "unconfined"
request-manager.cpp 113 runQueue Head: OnlineAccountsUi::Request(0x11a5490)
Invalid prompt session: Error processing request: Could not identify application session
Internal error details: /build/mir-YefCL3/mir-0.23.3+16.04.20160707.1/src/server/scene/prompt_session_manager_impl.cpp(137): Throw in function virtual std::shared_ptr<mir::scene::PromptSession> mir::scene::PromptSessionManagerImpl::start_prompt_session_for(const std::shared_ptr<mir::scene::Session>&, const mir::scene::PromptSessionCreationParameters&) const
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::runtime_error> >
std::exception::what: Could not identify application session

Couldn't setup prompt session
UiProxy initialization failed!

Is this the same as lp:1494197?

I start a new session, create the U1 account, then open the store and the account is removed.
So nothing else is running.

Syncing task from Mir.