This is patch-ac in pkgsrc (== is non-POSIX).  Please apply to CVS.
(And if cvs isn't the official repo, please explain that...)

Index: configure.ac
===================================================================
RCS file: /coda-src/coda/configure.ac,v
retrieving revision 1.27
diff -u -p -r1.27 configure.ac
--- configure.ac	10 Feb 2012 15:52:54 -0000	1.27
+++ configure.ac	1 Mar 2012 00:58:07 -0000
@@ -142,7 +142,7 @@ AC_SUBST(shortsys)
 dnl Build conditionals
 if test "$buildvcodacon" != no ; then
   test -z "${FLUID}" && AC_MSG_ERROR("Unable to find fltk-fluid")
-  test "$coda_cv_path_fltk" == none && AC_MSG_ERROR("Unable to find libfltk")
+  test "$coda_cv_path_fltk" = none && AC_MSG_ERROR("Unable to find libfltk")
 fi
 AM_CONDITIONAL(BUILD_VCODACON, [test "$buildvcodacon" != no])