Web.Config Transform not changing any values

Question

I'm trying to set up a web.config transform to modify some values. I am using this example given by Octopus Deploy:

http://docs.octopusdeploy.com/display/OD/Configuration+files

ultra-slimmed down version of web.config:

<?xml version="1.0" ?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <system.web>
    <compilation debug="true" targetFramework="4.0">
    </compilation>
  </system.web>
</configuration>

the transform:

<?xml version="1.0" ?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
  <system.web>
    <compilation xdt:Transform="RemoveAttributes(debug)" />
  </system.web>
</configuration>

the output:

<?xml version="1.0"?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <system.web>
    <compilation debug="true" targetFramework="4.0">
    </compilation>
  </system.web>
</configuration>

I'm using this tool to preview the transformation: https://webconfigtransformationtester.apphb.com/

as you can see it doesn't do anything. I've looked at a lot of examples, but obviously I'm missing something. Any help would be greatly appreciated.

(I've also tried this with no luck):

<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
  <system.web>
      <compilation debug="false" xdt:Transform="Replace">
      </compilation >
  </system.web>
</configuration>

Answer 1

The transform works as intended on the mentioned online preview tool for web.config transformations https://webconfigtransformationtester.apphb.com/ when you change the namespace of the web.config file from

<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">

to

<configuration xmlns:xdt="http://schemas.microsoft.com/.NetConfiguration/v2.0">

When this transform

<?xml version="1.0" ?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
  <system.web>
    <compilation xdt:Transform="RemoveAttributes(debug)" />
  </system.web>
</configuration>

is applied to the adjusted web.config

<?xml version="1.0" ?>
<configuration xmlns:xdt="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <system.web>
    <compilation debug="true" targetFramework="4.0">
    </compilation>
  </system.web>
</configuration>

the debug attribute is removed from the result:

<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <system.web>
    <compilation targetFramework="4.0">
    </compilation>
  </system.web>
</configuration>

Update: As mentioned in the comments, the configuration of the web.config file shouldn't have any namespace at all. Instead, it's necessary to add this import

<xdt:Import assembly="AppHarbor.TransformTester" 
            namespace="AppHarbor.TransformTester.Transforms"/>

to the transform file (at least, when testing with the mentioned online transformation tester):

<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
<xdt:Import assembly="AppHarbor.TransformTester" 
     namespace="AppHarbor.TransformTester.Transforms"/>
  <system.web>
    <compilation xdt:Transform="RemoveAttributes(debug)" />
  </system.web>
</configuration>