Hi, Pharo 2.0 is shipped with Metacello. Metacello version installed is based on the stable version (1.0-beta.31.1.5). This version loads Metacello-ToolBox-dkh.130 but strangely, the Metacello-ToolBox package shipped in Pharo 2.0 is Metacello-ToolBox-MarkusDenker.135. Its ancestor is Metacello-ToolBox-dkh131 but Metacello-ToolBox-dkh.130 is not its ancestor. It seems that Metacello-ToolBox-dkh131 is another branch and that Pharo 2.0 does not ship the right version of Metacello Toolbox. I found this with tests using the toolbox. They failed because the method configurationNameFrom behavior is not the same : Metacello-ToolBox-dkh.130>>Metacello-ToolBox>>configurationNameFrom: baseName "Return the fully-qualified configuration class name." <apiDocumentation> ^ (baseName indexOfSubCollection: 'ConfigurationOf') > 0 ifTrue: [ baseName ] ifFalse: [ 'ConfigurationOf' , baseName ] Metacello-ToolBox-MarkusDenker.135>>Metacello-ToolBox>>configurationNameFrom: baseName "Return the fully-qualified configuration class name." <apiDocumentation> self flag: 'More work needed based on MetacelloScriptEngine'. ^ baseName' => Here it is strange because the basename of a Configuration is the name without 'ConfigurationOf' and e expect to have as result 'ConfigurationOfXXX' So, 2 questions : is the Metacello-ToolBox-MarkusDenker.135 working? should we not use the same base version of Metacello-ToolBox as the one declared (Metacello-ToolBox-dkh.130) in Metacello 1.0-beta.31.1.5 configuration? Regards, Christophe.