using mirror requires to manually supply a path to the stack setup yaml for running stack setup

[AleXoundOS]

In order to run stack setup you have to supply a path to "mirror/stack-setup-mirror.yaml" manually with --setup-info-yaml option every time. This is due to inability of stack to use setup-info: field in "~/.stack/config.yaml" in a proper manner. See progress on these 2 issues related to improper treatment of it and possible fix: commercialhaskell/stack#2982 and commercialhaskell/stack#2983. The idea is that setup-info: field with a combination of urls: and package-indices in config.yaml file should be sufficient to perform any stack command using this offline mirror.