pkg/42926: m4 doesn't build because an include error

[tuxillo%leaf.dragonflybsd.org@localhost]

>Number:         42926
>Category:       pkg
>Synopsis:       m4 doesn't build because an include error
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 06 10:20:00 +0000 2010
>Originator:     Antonio Huete Jimenez
>Release:        N/A
>Organization:
DragonFlyBSD
>Environment:
DragonFly island.quantumachine.net 2.5.1-DEVELOPMENT DragonFly 
v2.5.1.881.gaabd5-DEVELOPMENT #11: Mon Feb 22 09:39:56 CET 2010     
antonioh%island.quantumachine.net@localhost:/usr/obj/home/source/dfbsd/sys/GENERIC_SMP
  i386
>Description:
Hi,

For m4 there's a specific fflush() version which only DragonFlyBSD is using at 
the moment. After the update to m4-1.4.14 we have realised that there's a 
problem include unistd.h (this is not our system specific version but the 
generated one by m4 build process) in the bsd-fflush.c file. 

Anyways, I see no specific reason why unistd.h should be included at all in tha 
file, plus removing that include will make m4 to be built.

We are investigating if there's a problem in our headers that messes up the 
things and causes unistd.h autogenerated file to be wrong.

In the mean time, could you please remove the #include <unistd.h> line from 
files/bsd-fflush.c? We cannot afford to have m4 broken because so many things 
depend on it.

Thanks,
Antonio Huete
>How-To-Repeat:
Here's the error:

--- fflush.o ---
In file included from ./unistd.h:74,
                 from fflush.c:36:
./getopt.h:195: error: redefinition of 'struct option'
*** [fflush.o] Error code 1
--- filenamecat.o ---
mv -f .deps/filenamecat.Tpo .deps/filenamecat.Po
1 error

bmake: stopped in /usr/pkgsrc/devel/m4/work/m4-1.4.14/lib
*** [all] Error code 2
1 error

bmake: stopped in /usr/pkgsrc/devel/m4/work/m4-1.4.14/lib
*** [all-recursive] Error code 1
1 error

bmake: stopped in /usr/pkgsrc/devel/m4/work/m4-1.4.14
*** [all] Error code 2
1 error

bmake: stopped in /usr/pkgsrc/devel/m4/work/m4-1.4.14
*** Error code 2

Stop.
bmake: stopped in /usr/pkgsrc/devel/m4
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/devel/m4

>Fix:
diff --git a/devel/m4/files/bsd-fflush.c b/devel/m4/files/bsd-fflush.c
index f0bdf4e..669a51f 100644
--- a/devel/m4/files/bsd-fflush.c
+++ b/devel/m4/files/bsd-fflush.c
@@ -33,7 +33,6 @@

 #include <errno.h>
 #include <stdio.h>
-#include <unistd.h>

 #undef fflush