issues with bsdgrep and lang/go

hi there,

i'm running HEAD on amd64 with bsdgrep (WITH_BSD_GREP=true). i noticed the
lang/go port won't build due to errors caused by egrep. this might be a ports
issue, but to me it rather looks like bsdgrep is not behaving exactly the same,
as gnu grep. however i haven't tried building the port with gnu grep. maybe
somebody could check that out. the port errors are of the following form:

[...]
gmake -C 6g install
gmake[1]: Entering directory `/usr/ports/lang/go/work/go-20110515/src/cmd/6g'
quietgcc -I"/usr/ports/lang/go/work/go-20110515/include" -ggdb -O2 -c "/usr/ports/lang/go/work/go-20110515/src/cmd/6g/list.c"
egrep: : error: .Each undeclared identifier|: error: for each function it appears|is dangerous, better use|is almost always misused|: In function |: At top level: |In file included from|        from: No such file or directory
quietgcc -I"/usr/ports/lang/go/work/go-20110515/include" -ggdb -O2 -c "/usr/ports/lang/go/work/go-20110515/src/cmd/6g/gobj.c"
egrep: : error: .Each undeclared identifier|: error: for each function it appears|is dangerous, better use|is almost always misused|: In function |: At top level: |In file included from|        from: No such file or directory
quietgcc -I"/usr/ports/lang/go/work/go-20110515/include" -ggdb -O2 -c "/usr/ports/lang/go/work/go-20110515/src/cmd/6g/galign.c"
egrep: : error: .Each undeclared identifier|: error: for each function it appears|is dangerous, better use|is almost always misused|: In function |: At top level: |In file included from|        from: No such file or directory
quietgcc -I"/usr/ports/lang/go/work/go-20110515/include" -ggdb -O2 -c "/usr/ports/lang/go/work/go-20110515/src/cmd/6g/ggen.c"
egrep: : error: .Each undeclared identifier|: error: for each function it appears|is dangerous, better use|is almost always misused|: In function |: At top level: |In file included from|        from: No such file or directory
quietgcc -I"/usr/ports/lang/go/work/go-20110515/include" -ggdb -O2 -c "/usr/ports/lang/go/work/go-20110515/src/cmd/6g/cgen.c"
egrep: : error: .Each undeclared identifier|: error: for each function it appears|is dangerous, better use|is almost always misused|: In function |: At top level: |In file included from|        from: No such file or directory
quietgcc -I"/usr/ports/lang/go/work/go-20110515/include" -ggdb -O2 -c -I. -o cplx.o ../gc/cplx.c
[...]

cheers.
alex