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git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33703 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/dbm/extconf.rb

@@ -17,7 +17,7 @@ headers = {
   "db5" => ["db5/db.h", "db5.h", "db.h"],
   "dbm" => ["ndbm.h"],
   "gdbm" => ["gdbm-ndbm.h", "ndbm.h", "gdbm/ndbm.h"],
-  "gdbm_compat" => ["gdbm-ndbm.h", "ndbm.h", "gdbm/ndbm.h"],
+  "gdbm_compat" => ["gdbm-ndbm.h", "ndbm.h", "gdbm/ndbm.h"], # ndbm compatibility routines are extracted to libgdbm_compat since gdbm-1.8.1.
   "qdbm" => ["relic.h", "qdbm/relic.h"],
 }