forConcurrently_ will spawn an unbounded number of threads. I guess we don’t care since the number of assets is small? If we do care, the easiest solution is usually just to throw a semaphore around the map function you pass to forConcurrently_.

The Bash code this replaces was also unbounded, so at least this is not getting worse. 🙂

I'm not concerned; we're not going to have a very big number of files anyway. If you are concerned, I can add a semaphore with, say, 30 slots, so it won't change anything for the happy path (16 assets atm) but will shield against future issues. I'd prefer to do that in a future PR, though.

Seems like we could just call wget directly and -o to avoid the cd but I’ll leave that up to you.

ì'm planning to remove wget in my next PR (perhaps next-next now, if the next one is the semaphore), so I don't see much point in trying to make the Bash code nicer. I would point though that we are not in the tmpdir in terms of Haskell process cwd as far as I can tell, so the cd there is not superfluous as it stands.