scratchpad papidave I've been banging my head on the table with Apache::Session::MySQL today. Consider:<p> <code> eval { ( my %session, $ok ); $ok = tie( %session, 'Apache::Session::MySQL', undef, ... ); if ( $ok ) { ... do something with %session ... } untie %session; } </code> This doesn't work from mod_perl, because the untie throws an exception: <blockquote> <tt> untie attempted while 1 inner references still exist at foo.pl line 250. </tt> </blockquote> Since I don't use any explicit references to <tt>%session</tt>, this caught me by surprise. Can you see the bug? <p> <spoiler> The trick here is to read the fine print on the return code provided by <tt>tie</tt>: <blockquote> The object returned by the constructor is in turn returned by the <tt>tie</tt> function, which can be useful if you want to access other methods in CLASSNAME </blockquote> In other words, I can't <tt>untie %session</tt> because <tt>$ok</tt> is still holding a reference to it. One fix is to assign <tt>$ok</tt> <i>to a constant</i> if and only if tie returns a non-false value, e.g.: <code> eval { ( my %session, $ok ); tie( %session, 'Apache::Session::MySQL', undef, ... ) and $ok = 1; if ( $ok ) { ... do something with %session ... } untie %session; } </code> This eliminates the duplicate reference to %session, so my session properly goes away. Thank you each for the alternate solutions suggested by monks in the CB: <ul> <li><c>if ( tie( ... ) ) { $ok = 1 }</c></li> <li><c>$ok = tie( ... ) && 1;</c></li> and one particularly elegant answer, from [tye]: <li><c>$ok = !! tie( ... );</c></li> </ul> </spoiler>