AC_INIT(foo)

AC_PROG_CC
AC_PROG_CPP

# Works ok
AC_CHECK_HEADER(popt.h,
	AC_CHECK_LIB(popt, poptGetNextOpt,
		foo=1,
		AC_MSG_ERROR(*** Cannot find popt library); exit),
	AC_MSG_ERROR(*** cannot find popt.h header); exit)

# Does not work
AC_CHECK_LIB(popt, poptGetNextOpt,
	AC_CHECK_HEADER(popt.h,
		foo=1,
		AC_MSG_ERROR(*** Cannot find popt.h header); exit),
	AC_MSG_ERROR(*** Cannot find popt library); exit)