emacs - can't find "cscope-index-recursively" variable when I do Meta-X, it only finds "cscope-index-files" -

repro:

1. open emacs

2. m-x cscope-index-recursively

   a. not find it, finds cscope-index-files

installed packages:

source: emacs23 version: 23.3+1-1ubuntu9.2   source: cscope  version: 15.7a-3.5  depends: cscope (>= 15.7a-3.5), emacs23 | emacsen 

cscope-index-recursively variable, not function, cannot invoque m-x. change value (and see description), type m-x customize-variable ret cscope-index-recursively