This was encoutered with XenForo 2.0.7, and I wasn't using the CLI options for installing VaultWiki ... just the standard web-based one through the admin cp.
I've since upgraded my local dev forum to 2.0.12 and tried to resume the installation (XF says Action pending, Last action: install:7). It still seems to be stuck in a loop, with 53 instances of step 7 now.