commit 3cc37a5e294048a52fa3c2aa2c1ed89b0cd07169
Author: Ian Stakenvicius <axs@gentoo.org>
Date:   Thu Aug 8 11:09:30 2013 -0400

    Fixed compile error when --enable-selinux
    
    FORMAT_TIMESPAN_MAX is used in src/udev/label.c in selinux-related
    code, but this was not defined as it is located in a shared header
    in systemd.  Added the define to label.h.  Didn't bother to track
    down what commit added (or removed) this code (define)
    
    Signed-off-by: Ian Stakenvicius <axs@gentoo.org>

diff --git a/src/udev/label.h b/src/udev/label.h
index 3d12ac2..507fd2c 100644
--- a/src/udev/label.h
+++ b/src/udev/label.h
@@ -25,6 +25,9 @@
 #include <stdbool.h>
 #include <sys/socket.h>
 
+/* from systemd src/shared/time-util.h */
+#define FORMAT_TIMESPAN_MAX 64
+
 int label_init(const char *prefix);
 void label_finish(void);