Hello.. i trying to load VMMaker using metacello config on linux .. and it seems like a file system/plugins working differently there, so during package loading i got FileExists exception (for .mcz files which happen to be already in package-cache). The error triggered in MCCacheRepository(MCDirectoryRepository)>>writeStreamForFileNamed: aString replace: aBoolean do: aBlock i don't know why it can't use cached version (since file already exists, it should, yes?) Try issuing following in pharo-1.3 core image(http://pharo-ic.lille.inria.fr/hudson/job/Pharo%20Core%201.3/) Gofer new squeaksource: 'MetacelloRepository'; package: 'ConfigurationOfCog'; load. ((Smalltalk at: #ConfigurationOfCog) project version: '1.2') load. on mac it works well. Update: It appears that the bug triggers only if you have wiped-clean package-cache dir , which is always true in my setup, because i do 'rm -rf build' before starting putting things there. Here the package-cache contents at the moment of error: ls package-cache/ ConfigurationOfCog-IgorStasenko.4.mcz ConfigurationOfMetacello-DaleHenrichs.554.mcz Metacello-Core-DaleHenrichs.455.mcz ConfigurationOfHelpSystem-DaleHenrichs.13.mcz Metacello-Base-DaleHenrichs.19.mcz Metacello-MC-DaleHenrichs.505.mcz i need help with it.. because it looks like a bad karma.. each time i think that my build setup is ready to roll, some shitty thing pops up and blocks me from finishing things i do. Before that i was using a script which were simply loaded a list of .mcz packages from corresponding locations. And everything just worked, except that i chosen to use metacello.. to not have problems to deal with need to load different packages for different forks, but now metacello blocks me. :( -- Best regards, Igor Stasenko AKA sig.