Patch taken from homebrew formula.
Removed gtk-mac-integration dependency.
https://github.com/Homebrew/homebrew-core/blob/cd1e31a/Formula/gspell.rb
diff --git a/gspell/Makefile.am b/gspell/Makefile.am
index 076a9fd..6c67184 100644
--- a/gspell/Makefile.am
+++ b/gspell/Makefile.am
@@ -155,6 +156,12 @@ gspell_private_headers += \
 gspell_private_c_files += \
	gspell-osx.c

+libgspell_core_la_CFLAGS += \
+	-xobjective-c
+
+libgspell_core_la_LDFLAGS += \
+	-framework Cocoa
+
 endif # OS_OSX

 if HAVE_INTROSPECTION