prefer-remote-fetch: add extendMkDerivation-based approach#457426

ShamrockLee wants to merge 1 commit intoNixOS:masterNixOS/nixpkgs:masterfrom

ShamrockLee:prefer-remote-fetch-extendMkDerivationShamrockLee/nixpkgs:prefer-remote-fetch-extendMkDerivationCopy head branch name to clipboard