android - Error:(12, 32) error: attribute value must be constant when declaring String for toast for ACRA toast -

i'm trying introduce acra lib in library project. when set string toast, "attribute value must constant" error. please see attached screen-shots

and r.string.crash_toast_text:

please note these lines of code here

https://github.com/acra/acra/wiki/advancedusage#toast-notification

based on commonsware 18 answer, made work. here sample code if gets stuck in same situation:

 final acraconfiguration config = acra.getnewdefaultconfig(this);      try {         config.setmode(reportinginteractionmode.toast);     } catch (acraconfigurationexception e) {         e.printstacktrace();     }      config.setrestoasttext(r.string.crash_toast_text);     acra.init(this, config);