I would expect aclocal to fail and terminate the build script if warnings appear [1]; however, it does not happen:
== Steps to reproduce == { cat >configure.ac <<'#>configure.ac' && aclocal -W error && echo $?; } AC_INIT([name],[0.0.1]) AC_CANONICAL_TARGET AM_INIT_AUTOMAKE AC_COMPILE_IFELSE() AC_USE_SYSTEM_EXTENSIONS #>configure.ac == Actual results == configure.ac:26: warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS 0 == Expected results == configure.ac:26: warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS == Workaround == { WARNINGS=error aclocal; } aclocal: autom4te failed with exit status: 1 == Remarks == It seems that aclocal fails to pass -Werror to autom4te. ___ [1] <URL: http://sources.redhat.com/automake/automake.html#aclocal-Options >