Curious error messages when building ports?

[Torfinn Ingolfsen]

Hello,

I hav seen this on FreeBSD 6-stable recently.
Here is an example, from a machine running
tingo at kg-work$ uname -a
FreeBSD kg-work.kg4.no 6.2-STABLE FreeBSD 6.2-STABLE #2: Sat Jan 20 17:26:43 CET 2007     root at kg-work.kg4.no:/usr/obj/usr/src/sys/SS51G  i386
I cd into /usr/ports/audio/gxmms2 and issue the command 'make'.
Before it actually starts to build, I get lots of lines like these on screen:
grep: writing output: Broken pipe
grep: writing output: Broken pipe
grep: writing output: Broken pipe
grep: writing output: Broken pipe
grep: writing output: Broken pipe

Anyone know what's causing this?
-- 
Regards,
Torfinn Ingolfsen,
Norway