\documentclass{ltxdoc}

\AlsoImplementation
\RecordChanges
\CodelineIndex
\EnableCrossrefs

\GetFileInfo{listbib.dtx}

\usepackage{scrlfile}
\newcommand*{\RestoreUnderscore}{}
\BeforePackage{inputenc}{%
  \edef\RestoreUnderscore{\catcode95=\the\catcode95 \relax}%
  \catcode95=8 \relax
}
\AfterPackage{inputenc}{\RestoreUnderscore}

\errorcontextlines=100
\usepackage{listbib}

\begin{document}
\DocInput{listbib.dtx}
\PrintChanges
\PrintIndex
\end{document}