AM_INIT_AUTOMAKE([-Wall -Wno-extra-portability]) 

automake: warnings are treated as errors
/usr/share/automake-1.14/am/ltlibrary.am: warning: 'libsnappy.la': linking libtool libraries using a non-POSIX
/usr/share/automake-1.14/am/ltlibrary.am: archiver requires 'AM_PROG_AR' in 'configure.ac'
Makefile.am:4:   while processing Libtool library 'libsnappy.la'
make: *** [install_snappy] Error 1