phpmyadmin needs a php with the pcre useflag - otherwise you get "Fatal error: Call to undefined function: preg_replace()"
<snip> if ! PHPCHECKNODIE="yes" require_php_with_use pcre session unicode \ || ! PHPCHECKNODIE="yes" require_php_with_any_use mysql mysqli ; then eerror eerror "${PHP_PKG} needs to be re-installed with all of the following" eerror "USE flags enabled:" eerror eerror "pcre session unicode" eerror eerror "as well as any of the following USE flags enabled:" eerror eerror "mysql or mysqli if using dev-lang/php-5" eerror "mysql if using dev-lang/php-4" eerror die "Re-install ${PHP_PKG}" fi </snip>
I have got another php-version (php5) with pcre installed - that was the reason :(