I am having problems trying to use user defined labels in org export to
LaTeX (beamer specifically).

If I have the following org,

#+begin_src org
  ,#+TITLE: LaTeX export minimal test
  ,* Intro
  :PROPERTIES:
  :CUSTOM_ID: introduction
  :END:
  This is the first slide.
  ,* Summary
  As we saw on slide [[#introduction]], ...
#+end_src

I get the following LaTeX generated:

#+begin_src latex
  \begin{frame}[label=introduction]{Intro}
  This is the first slide.
  \end{frame}

  \begin{frame}[label={sec:orgdc0a2c3}]{Summary}
  As we saw on slide \ref{sec-1}, \ldots{}
  \end{frame}
#+end_src

(elided for size).  Note that internally generated labels of the form
orgXXXXXX are not generated but instead org generates "sec-1" instead of
using \ref{introduction}.

I have org-latex-prefer-user-labels set to t.

Am I doing something wrong or is this a bug in org?  I'm up to date with
git version as of a few minutes ago.

Thanks,
eric

-- 
: Eric S Fraga (0xFFFCF67D), Emacs 26.0.50.1, Org release_9.0.1-125-g93b43e