hi, I've got this "not enough memory" twice today while trying to upgrade some packages using zef. Once when I ran 'zef upgrade zef' and then again when I ran 'zef --debug upgrade Bailador'.
In both cases the error was shown during the running of the tests. After running the first command again it worked. The second command kept the same error message. This machine had 1 Gb memory. After adding another Gb the second command worked as well. Gabor