In Subversion at least, you'd do a partial checkout. If you don't need a particular directory you just don't check it out. If you lay out your repo structure well there's no problem. It was incredibly convenient.
I've tried many different SCM over the years and I was happy when git took root, but its poor handling of large files was problematic from the beginning. Git being bad at large files turned into this best practice of not storing large files in git, which was shortened to "don't store large files in SCM." I think that's a huge source of our availability and/or supply chain headache.
I have projects from 20 years ago that I can build because all of the dependencies (minus the compiler -- I'm counting on it being backwards compatible) are stored right in the source code. Meanwhile, I can't do that with Ruby projects from several years ago because gems have been removed. I've seen deployments come to a halt because no startup runs its own package server mirror and those servers go offline or a package may get deleted mid-deploy. The infamous leftpad incident broke a good chunk of the web and that wouldn't have happened if that package was fetched once and then added to an appropriate SCM. Every time we fetch the same package repeatedly from a package server we're counting on it having not changed because no one does any sort of verification any longer.
I've tried many different SCM over the years and I was happy when git took root, but its poor handling of large files was problematic from the beginning. Git being bad at large files turned into this best practice of not storing large files in git, which was shortened to "don't store large files in SCM." I think that's a huge source of our availability and/or supply chain headache.
I have projects from 20 years ago that I can build because all of the dependencies (minus the compiler -- I'm counting on it being backwards compatible) are stored right in the source code. Meanwhile, I can't do that with Ruby projects from several years ago because gems have been removed. I've seen deployments come to a halt because no startup runs its own package server mirror and those servers go offline or a package may get deleted mid-deploy. The infamous leftpad incident broke a good chunk of the web and that wouldn't have happened if that package was fetched once and then added to an appropriate SCM. Every time we fetch the same package repeatedly from a package server we're counting on it having not changed because no one does any sort of verification any longer.