title: Trac: report execution failed: Dynamic variable '$MYVAR' not defined
body: <p>I'm trying to develop a custom report for trac using SQL.  On one of my trac instaces, if I specify I dynamic variable like $MYVAR, it will show a little form on the report where I can fill in that value.  On other instances, I get an error that says "Report execution failed: Dynamic variable '$MYVAR' not defined.".  Why am I getting this error?</p>
  
  <p>The servers where this works are well established trac instances with a MySQL db.  The server with the error is a fresh install running SQLite.</p>
  
  <p>The sample query I'm running is:</p>
  
  <pre><code>SELECT 
    t.id AS ticket, t.version, t.time AS created, test_four.value as 'My Select'
  FROM 
    ticket t
  LEFT OUTER JOIN ticket_custom test_four ON
    (t.id = test_four.ticket AND test_four.name = 'test_four')
  WHERE
    (test_four.value like '$MYVAR' or (test_four.value is null and '$MYVAR' = '%'))
  </code></pre>
  
  <p>with </p>
  
  <pre><code>[ticket-custom]
  test_four = select
  test_four.label = My selectbox
  test_four.options = |one|two|third option|four
  test_four.value =
  </code></pre>
  
  <p>as the custom field config. Thanks for the help.</p>