Use AC_TRY_LINK to correctly detect db_version in a copy of libdb which has
been built with the --with-uniquename flag.
--- nss_db-2.2/configure.in	2003-12-02 16:22:42.000000000 -0500
+++ nss_db-2.2/configure.in	2003-12-02 16:22:37.000000000 -0500
@@ -43,8 +43,12 @@
 AC_CHECK_HEADER(db.h,, AC_MSG_ERROR([
 *** Could not find Berkeley DB headers.]))
 
-AC_CHECK_LIB(db, db_version,, AC_MSG_ERROR([
-*** Could not find Berkeley DB library.]))
+AC_CHECK_LIB(db, db_version,,[
+libsave="$LIBS"
+LIBS="$LIBS $DB_LIBS -ldb"
+AC_MSG_CHECKING([for db_version in -ldb using the linker])
+AC_TRY_LINK([#include <db.h>],[db_version(0,0,0);],[libsave="$libsave -ldb";AC_MSG_RESULT([yes])],[AC_MSG_RESULT([no]);AC_MSG_ERROR([*** Could not find Berkeley DB library.])])
+LIBS="$libsave"])
 
 AC_CACHE_CHECK([Berkeley DB version], nss_db_cv_db_version,
   [AC_TRY_CPP(