System Errors ============= System Errors are errors representing a system failure. At the application level, they are errors that are uncaught by the application and that a developer hasn't provided a custom error view for. Zope provides a default system error view that prints an obnoxius terse message and that sets the response status. To see an example of this, we'll create a ZPT page with an intentional error: >>> print http(r""" ... POST /+/zope.app.zptpage.ZPTPage%3D HTTP/1.1 ... Authorization: Basic mgr:mgrpw ... Content-Length: 739 ... Content-Type: multipart/form-data; boundary=---------------------------125598457818223697821067764270 ... Referer: http://localhost:8081/+/zope.app.zptpage.ZPTPage= ... ... -----------------------------125598457818223697821067764270 ... Content-Disposition: form-data; name="field.source" ... ... ... -----------------------------125598457818223697821067764270 ... Content-Disposition: form-data; name="field.expand.used" ... ... ... -----------------------------125598457818223697821067764270 ... Content-Disposition: form-data; name="field.evaluateInlineCode.used" ... ... ... -----------------------------125598457818223697821067764270 ... Content-Disposition: form-data; name="UPDATE_SUBMIT" ... ... Add ... -----------------------------125598457818223697821067764270 ... Content-Disposition: form-data; name="add_input_name" ... ... test.html ... -----------------------------125598457818223697821067764270-- ... """) HTTP/1.1 303 See Other ... Location: http://localhost/@@contents.html ... When we visit it, we get a terse error and a 500 status: We get a system error, because the problem is in the template, not in the URL: >>> print http(r""" ... GET /test.html HTTP/1.1 ... """) HTTP/1.1 500 Internal Server Error ... A system error occurred. ... Another way of getting a system error is the occurrence of a system error, such as ``ComponentLookupError``. I have registered a simple view in ``exception-ftesting.zcml`` that will raise a component lookup error. So if we call ``componentlookuperror.html``, we should get the error message: >>> print http(r""" ... GET /componentlookuperror.html HTTP/1.1 ... """) HTTP/1.1 500 Internal Server Error ... A system error occurred. ...