-# Checks for header files.
-# These are already checked: inttypes.h dlfcn.h memory.h stdint.h stdlib.h
-# string.h strings.h sys/types.h sys/stat.h unistd.h
-AC_CHECK_HEADERS([errno.h fcntl.h stddef.h sys/ioctl.h termios.h])
+# Checks for libraries.
+
+# This variable collects the pkg-config names of all detected libs.
+# It is then used to construct the "Requires.private:" field in the
+# libserialport.pc file.
+SP_PKGLIBS=""