Bug fix for with_system_path for Linuxbrew
Bug fix for with_system_path for Linuxbrew

Closes Homebrew/linuxbrew#436

Linuxbrew/brew,Linuxbrew/brew,hanxue/linuxbrew,hanxue/linuxbrew,hanxue/linuxbrew,rwhogg/brew,Linuxbrew/brew,rwhogg/brew,maxim-belkin/brew,maxim-belkin/brew,rwhogg/brew,maxim-belkin/brew,Linuxbrew/brew