Set a relative path to cache dir

DVC from sources:

$ dvc -V
0.20.0+c4295f.mod

$ git clone https://github.com/iterative/so-dataset-posts-25K
$ cd so-dataset-posts-25K/
$ dvc config cache.dir ../mycache
$ dvc pull
....
$ ls mycache # <-- it suppose to be one level up ../mycache
2f

Btw… it works just fine if I use an absolute path like in this example dvc config cache.dir /dvc-cache: https://dvc.org/doc/use-cases/multiple-data-scientists-on-a-single-machine

[ghost]

I moved the issue to dvc.org to add a better explanation of this behavior on the docs.

[efiop]

I’ve used worktree as an example, but there other ones like include sections in git config. See https://git-scm.com/docs/git-config#_conditional_includes . And once again, relative paths in them are resolved relative to the config file location, which is correct and expected behavior. And git doesn’t introduce a separate command git include to do that single action. And I also see no reason to bloat our CLI with yet another command just to provide an implicit behavior, when we already have dvc config cache.dir that has consistent behavior on all levels.