I try to install GitFileTree on Pharo and I get this warning

This package depends on the following classes: StringHolder You must resolve these dependencies before you will be able to load these definitions: CrLfFileEditor CrLfFileEditor>>#defaultLineEndConvention CrLfFileEditor>>#editFileNamed: CrLfFileEditor>>#fileNamed: CrLfFileEditor>>#fileNamed:inDirectoryPath: CrLfFileEditor>>#fileNamed:withLabel: CrLfFileEditor>>#initialize CrLfFileEditor>>#on:withLabel:inDirectory:defaultFileName: CrLfFileEditor>>#on:withLabel:inDirectory:defaultFileName:lineEndConvention: CrLfFileEditor>>#openForFileNamed: CrLfFileEditor>>#openOn:withLabel:inDirectory:defaultFileName: CrLfFileEditor>>#openOn:withLabel:inDirectory:defaultFileName:lineEndConvention: CrLfFileEditor>>#windowColorSpecification CrLfFileEditor>>#bogusTruncate: CrLfFileEditor>>#browseChanges CrLfFileEditor>>#contents CrLfFileEditor>>#contents: CrLfFileEditor>>#controllerForAccept CrLfFileEditor>>#currentFilePathName CrLfFileEditor>>#defaultFont CrLfFileEditor>>#directory: CrLfFileEditor>>#exit CrLfFileEditor>>#fileContentsMenu:shifted: CrLfFileEditor>>#fileName: CrLfFileEditor>>#forceDirtyBuffer CrLfFileEditor>>#getAnotherFileName: CrLfFileEditor>>#getFileName: CrLfFileEditor>>#getHex CrLfFileEditor>>#getSelection CrLfFileEditor>>#getText CrLfFileEditor>>#hexFormat: CrLfFileEditor>>#labelString CrLfFileEditor>>#lineEndConvention: CrLfFileEditor>>#mvcWithLabel: CrLfFileEditor>>#openAsMorphLabel: CrLfFileEditor>>#openLabel: CrLfFileEditor>>#put: CrLfFileEditor>>#save CrLfFileEditor>>#saveAs CrLfFileEditor>>#selectedClassOrMetaClass CrLfFileEditor>>#selectedMessageCategoryName CrLfFileEditor>>#updateFilePathWith: CrLfFileEditor>>#viewStyle: CrLfFileEditor>>#withLabel: Select Proceed to continue, or close this window to cancel the operation.