すいません、エラーメッセージはこちらが重要なのかもしれません
毎回出るのでこれはふつうのメッセージだと思っていたのですが、
どうなんでしょうか。

# javac
libgcj-javac-placeholder.sh

This script is a placeholder for the /usr/bin/javac
master link required by jpackage.org conventions. libgcj's
rmiregistry, rmic and jar tools are now slave symlinks to these
masters, and are managed by the alternatives(8) system.

This change was necessary because the rmiregistry, rmic and jar tools
installed by previous versions of libgcj conflicted with symlinks
installed by jpackage.org JVM packages.
gcj: no input files