ubufox causes deprecation warning in firefox-trunk nsIBrowserSearchService#async_warning

[Adrian [e-mail]]

I am running firefox-trunk on Ubuntu 15.04 and here is the warning from the browser console:

    DEPRECATION WARNING: Search service falling back to synchronous initialization. This is generally the consequence of an add-on using a deprecated search service API.
    You may find more details about this deprecation at: https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIBrowserSearchService#async_warning
    resource://gre/components/nsSearchService.js 3174 SRCH_SVC__ensureInitialized
    resource://gre/components/nsSearchService.js 4474 SearchService.prototype.currentEngine
    resource://ubufox/distributions/Ubuntu.jsm 85 getProviderForCurrentSearchEngine
    resource://ubufox/distributions/Ubuntu.jsm 146 DistroImpl.startpageURI
    resource://ubufox/modules/Distro.jsm 119 distro.startpageURI
    file:///usr/share/mozilla/extensions/%7Bec8030f7-c20a-464f-9b0e-13a3a9e97384%<email address hidden>/components/AboutStartpage.js 68 AboutStartpage.prototype.newChannel
    chrome://browser/content/browser.js 11887 _loadURIWithFlags
    chrome://browser/content/tabbrowser.xml 5967 loadURIWithFlags
    chrome://global/content/bindings/browser.xml 119 loadURI
    chrome://browser/content/tabbrowser.xml 3453 loadURI
    chrome://browser/content/tabbrowser.xml 1461 loadTabs
    chrome://browser/content/browser.js 12838 loadOneOrMoreURIs
    chrome://browser/content/browser.js 12221 gBrowserInit._delayedStartup
    null 0 null