The linker command line uses $CXX anyway, so explicitly linking -lstdc++ is unnecessary.
Index: patches/patch-configure =================================================================== RCS file: /cvs/ports/audio/grip/patches/patch-configure,v retrieving revision 1.7 diff -u -p -r1.7 patch-configure --- patches/patch-configure 29 Aug 2017 16:43:59 -0000 1.7 +++ patches/patch-configure 14 Jan 2019 15:22:25 -0000 @@ -2,7 +2,7 @@ $OpenBSD: patch-configure,v 1.7 2017/08/ Index: configure --- configure.orig +++ configure -@@ -4968,7 +4968,7 @@ fi +@@ -4981,7 +4981,7 @@ fi done @@ -11,3 +11,25 @@ Index: configure do : as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh` ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default" +@@ -16611,7 +16611,7 @@ return ID3Tag_Link (); + return 0; + } + _ACEOF +-for ac_lib in '' "id3 -lz -lstdc++"; do ++for ac_lib in '' "id3 -lz"; do + if test -z "$ac_lib"; then + ac_res="none required" + else +@@ -16646,10 +16646,10 @@ $as_echo "#define HAVE_ID3V2 /**/" >>confdefs.h + + if test "$enable_shared_id3" = "yes"; then + echo "using shared id3lib" +- ID3_LIBS="-lid3 -lz -lstdc++" ++ ID3_LIBS="-lid3 -lz" + else + echo "using static id3lib" +- ID3_LIBS="$prefix/lib/libid3.a -lz -lstdc++" ++ ID3_LIBS="$prefix/lib/libid3.a -lz" + fi + else + id3lib=no