bug#42136: 26.1.90; rgrep uses a directory that was not actually given

[Juri Linkov]

> Also I wanted to hear if anybody has a tip about some customization that
> I was missing.

Maybe some advice might help you:

(advice-add 'read-directory-name :around
            (lambda (orig-fun prompt &optional dir default-dirname
                              mustmatch initial)
              (cond
               ((equal prompt "Base directory: ")
                (funcall orig-fun prompt dir default-dirname
                         nil initial))
               (t
                (funcall orig-fun prompt dir default-dirname
                         mustmatch initial))))
            '((name . read-directory-name-no-mustmatch)))

It overrides the MUSTMATCH argument of read-directory-name in rgrep.