patch 7.4.924
Problem:    DEVELOPER_DIR gets reset by configure.
Solution:   Do not reset DEVELOPER_DIR when there is no --with-developer-dir
            argument. (Kazuki Sakamoto, closes #482)
diff --git a/src/auto/configure b/src/auto/configure
index f2f34d9..1acf7da 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -4198,7 +4198,7 @@
   withval=$with_developer_dir; DEVELOPER_DIR="$withval"; { $as_echo "$as_me:${as_lineno-$LINENO}: result: $DEVELOPER_DIR" >&5
 $as_echo "$DEVELOPER_DIR" >&6; }
 else
-  DEVELOPER_DIR=""; { $as_echo "$as_me:${as_lineno-$LINENO}: result: not present" >&5
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: not present" >&5
 $as_echo "not present" >&6; }
 fi