[crabbone]

We used this in Gitlab CI. Unfortunately, the only way they deal with artifacts is by putting them in Zip files. Cache between builds would thus be stored as a Zip file. However, fully extracting it before each build would sometimes take as much, if not more time than to just build fresh. Mounting a Zip file as a filesystem allows extracting entries on-demand, at the time a file access would've been made. This was a notable speedup in our compilation process.

[pizzafeelsright]

tar is what you're looking for, no?

[crabbone]

It was a while ago, and I haven't used Gitlab in a few years. Maybe they've added TAR as an option since, but Zip was the only option at that time.