AC_CHECK_HEADERS(sys/poll.h)
AC_REPLACE_FUNCS(mmap)
+if ! hash pkg-config; then
+ echo "ERROR: pkg-config is needed..."
+ exit 1
+fi
+
# Checks for libraries.
PKG_CHECK_MODULES(USB, libusb-1.0 >= 1.0.0,,
AC_MSG_ERROR([*** Required libusb-1.0 >= 1.0.0 not installed ***]))