[panki27]

   $ git clone --no-checkout $URL/repo.git
   $ cd repo/
   $ git sparse-checkout init
   $ git sparse-checkout set subdirectory_i_want
   $ git checkout main

[cakoose]

Now I'm curious -- is that here a way to do this that avoids downloading any more than strictly necessary?

The command above downloads the whole repo history. You could do a depth=1 to skip the history, but it still downloads the he latest version of the entire repo tree.

[craftkiller]

You could do a blobless or treeless clone https://github.blog/open-source/git/get-up-to-speed-with-par...

Combined with --depth=1 and the --no-checkout / --sparse-checkout flow that the GP already described.

I just tested on the emacs repo, left column is disk usage of just the `.git` folder inside:

  Shallow clones (depth=1):
  124K: Treeless clone depth=1 with no-checkout
  308K: Blobless clone depth=1 with no-checkout
  12M: Treeless clone depth=1 sparse checkout of "doc" folder
  12M: Blobless clone depth=1 sparse checkout of "doc" folder
  53M: Treeless clone depth=1 non-sparse full checkout
  53M: Blobless clone depth=1 non-sparse full checkout
  53M: Regular clone with depth=1

  Non-shallow clones:
  54M: Treeless clone with no-checkout
  124M: Blobless clone with no-checkout
  65M: Treeless clone sparse checkout of "doc" folder
  135M: Blobless clone sparse checkout of "doc" folder
  107M: Treeless clone with non-sparse full checkout
  177M: Blobless clone with non-sparse full checkout
  653M: Full regular git clone with no flags

Great tech talk covering some of the newer lesser-known git features: https://www.youtube.com/watch?v=aolI_Rz0ZqY

[vient]

git-archive downloads only strictly necessary files but is not universally supported

https://git-scm.com/docs/git-archive

[archargelod]

The rust app just calls a few git commands too[1]

Could've been a shell script[2]

[1] https://github.com/zikani03/git-down/blob/cb2763020edc81e464...

[2] https://textbin.net/ja17q8vga4