\documentclass[a4paper]{ltxdoc}
\usepackage[version=latest]{pgf}
\usepackage{xkeyval,calc,listings,tikz,fp,amsmath,amssymb}
\usepackage[T1]{fontenc}%
\usepackage{makeidx}
\makeindex
\usepackage{hyperref}
\hypersetup{%
        colorlinks=true,
        linkcolor=blue,
        filecolor=blue,
        urlcolor=blue,
        citecolor=blue,
        pdfborder=0 0 0,
}
\makeatletter          % see https://tex.stackexchange.com/q/33946
\input{pgfmanual.code} % 
\makeatother           % 
\input{pgfmanual-en-macros.tex} % link from
% /usr/local/texlive/2019/texmf-dist/doc/generic/pgf/macros/pgfmanual-en-macros.tex
% or the equivalent on your installation
\def\pgfautoxrefs{1}
\usetikzlibrary{bbox}
\begin{document}
\input{pgfmanual-en-library-bbox.tex}
\end{document}