Package `Versions' Warning: Redefining environment

Question

I am using the versions.sty package and would like to process some text twice (or more times) in a different version configuration, but within the same document. So I use \excludeversion and \includeversion several times. Each use of these seems to define the environment with the same parameter as the name of the argument. So I get an annoying warning at every run, cluttering my LaTeX messages.

Here is a small example:

\documentclass{book}
\usepackage{versions}

\begin{document}

\includeversion{A}
\excludeversion{B}

\begin{A}a\end{A}
\begin{B}b\end{B}

\excludeversion{A}
\includeversion{B}

\begin{A}a\end{A}
\begin{B}b\end{B}

\end{document}

Produces the following warnings:

Package `Versions' Warning: Redefining environment `A' on input line 11.
Package `Versions' Warning: Redefining environment `B' on input line 12.

And the following output:

a
b

The output is fine. Is there a better way of doing what I am trying to achieve without this warnings?

(of course the idea is that the text that is repeated in MWE is included from the same file, so I obtain different run of latex over the same file).

Answer 1

You can suppress the warnings issued by versions by adding the following to your preamble:

\makeatletter
\let\@Vs@envwarn\@gobble% Remove environment renewal warnings.
\makeatother

Alternatively the silence package does something similar:

\usepackage{silence}
\WarningFilter{`Versions'}{Redefining environment}

A different approach that uses \if-constructions would be:

\documentclass{article}
\newif\ifVersionA
\newif\ifVersionB
\begin{document}

\VersionAtrue% Include Version A
\VersionBfalse% Exclude Version B

\ifVersionA a \fi
\ifVersionB b \fi

\VersionAfalse% Exclude Version A
\VersionBtrue% Include Version B

\ifVersionA a \fi
\ifVersionB b \fi

\end{document}