Maybe? MSI and AIX use a fixed temp dir, e.g., https://github.com/opscode/omnibus-ruby/blob/master/lib/omnibus/project.rb#L658

`Dir.mktmpdir` has some security benefits in that the path won't be known ahead of time, but is harder to use when things go wrong because you have to hunt around for the particular dir used for the failed build. It also means we would need to do extra work to clean up (which means we have to either delete everything on a build failure, or else the user has to clean up manually after failed builds).