The low-level event-based API never existed so this statement
in the man page is wrong. If you want an asynchronous API, use
threads.
guestfs_close (handle);
C<guestfs_launch> and all of the actions including C<guestfs_sync>
-are blocking calls. You can use the low-level event API to do
-non-blocking operations instead.
+are blocking calls.
All functions that return integers, return C<-1> on error. See
section L</ERROR HANDLING> below for how to handle errors.