\documentclass{beamer}

{% from "macros.tex" import show_item %}


\begin{document}
{% include "provides.tex" %}

\begin{frame}
\begin{itemize}
{%- call show_item(item, spec, mode=mode) -%}
    {{ extra }}
{%- endcall %}
\end{itemize}
\end{frame}
\end{document}