--- rrdcollect-0.2.9/src/checkpid.c 2009-12-06 19:18:19.000000000 +0000 +++ rrdcollect-20120209/src/checkpid.c 2010-02-18 12:35:53.000000000 +0000 @@ -20,6 +20,7 @@ #include "rrdcollect.h" #include <fcntl.h> +#include <sys/file.h> /* lockfile in rrdcollect.pid */ /* five digits+"\n\0" */