[oe] Error while running bibake

[vivek tambakad]

hi
I want cross compile linphone for compulab EM-x270 board.when i try
   sudo bitbake -b
/home/development/em-x270/stuff/openembedded/recipes/linphone/
linphone_3.1.0.bb
    then i will get the following error
   *bb.parse.ParseError: Could not inherit file classes/autotools.bbclass
*
    pleasse guide me in compiling linphone for compulab board.

   with regards
   vivek tambakad