Finally got around to fixing the Archive page on this site.
If I recall correctly, what happened originally is that I was attempting to get rid of the “/blog/” part of the archive path, but got distracted halfway through and left it incomplete.
For reference: this part of the archive path is not a user-configurable part of Octopress per se. It is a default location for a file in Jekyll, which is in
source/blog/archive in an Octopress site repository. Simply moving the
archive/ folder out of
blog/ and into the top level of
source/ will make the archive page generate without the “/blog/” part of the page. (For further reference, see the workaround post on the issue on Github)