+=head1 error: pasting ")" and "l" does not give a valid preprocessing token
+
+There seems to be a broken system header file in HP-UX 11.00 that
+breaks perl building in 32bit mode with GNU gcc-4.x causing this
+error. The same file for HP-UX 11.11 (even though the file is older)
+does not show this failure, and has the correct definition, so the
+best fix is to patch the header to match:
+
+ --- /usr/include/inttypes.h 2001-04-20 18:42:14 +0200
+ +++ /usr/include/inttypes.h 2000-11-14 09:00:00 +0200
+ @@ -72,7 +72,7 @@
+ #define UINT32_C(__c) __CONCAT_U__(__c)
+ #else /* __LP64 */
+ #define INT32_C(__c) __CONCAT__(__c,l)
+ -#define UINT32_C(__c) __CONCAT__(__CONCAT_U__(__c),l)
+ +#define UINT32_C(__c) __CONCAT__(__c,ul)
+ #endif /* __LP64 */
+
+ #define INT64_C(__c) __CONCAT_L__(__c,l)
+
+=head1 Redeclaration of "sendpath" with a different storage class specifier
+
+The following compilation warnings may happen in HP-UX releases
+earlier than 11.31 but are harmless:
+
+ cc: "/usr/include/sys/socket.h", line 535: warning 562: Redeclaration of "sendfile" with a different storage class specifier: "sendfile" will have internal linkage.
+ cc: "/usr/include/sys/socket.h", line 536: warning 562: Redeclaration of "sendpath" with a different storage class specifier: "sendpath" will have internal linkage.
+
+They seem to be caused by broken system header files, and also other
+open source projects are seeing them. The following HP-UX patches
+should make the warnings go away:
+
+ CR JAGae12001: PHNE_27063
+ Warning 562 on sys/socket.h due to redeclaration of prototypes
+
+ CR JAGae16787:
+ Warning 562 from socket.h sendpath/sendfile -D_FILEFFSET_BITS=64
+
+ CR JAGae73470 (11.23)
+ ER: Compiling socket.h with cc -D_FILEFFSET_BITS=64 warning 267/562
+
+=head1 Miscellaneous
+
+HP-UX 11 Y2K patch "Y2K-1100 B.11.00.B0125 HP-UX Core OS Year 2000
+Patch Bundle" has been reported to break the io/fs test #18 which
+tests whether utime() can change timestamps. The Y2K patch seems to
+break utime() so that over NFS the timestamps do not get changed
+(on local filesystems utime() still works). This has probably been
+fixed on your system by now.
+