Hello,

compiling sed from git (v4.2.2-89-ge387009) fails with gcd-5.2 due to -Wunused-macros (and -Werror):

===
make[3]: Entering directory `/home/gordon/sources/sed/sed'
   CC       compile.o
compile.c:36:0: error: macro "OPEN_BRACE" is not used [-Werror=unused-macros]
  #define OPEN_BRACE '{'
  ^
compile.c:183:0: error: macro "END_ERRORS" is not used [-Werror=unused-macros]
  #define END_ERRORS (INCOMPLETE_CMD + sizeof(N_("incomplete command")))
  ^
cc1: all warnings being treated as errors
make[3]: *** [compile.o] Error 1
===

The attached patch comments-out the two macros. Alternatively they could be simply erased.

regards,
  - assaf

P.S.
I don't yet have copyright assignment for sed, but I think this change is trivial enough.