Add failing spec for `SystemCommand`.
Add failing spec for `SystemCommand`.

konqui/brew,EricFromCanada/brew,sjackman/homebrew,Homebrew/brew,vitorgalvao/brew,JCount/brew,vitorgalvao/brew,DomT4/brew,MikeMcQuaid/brew,reitermarkus/brew,reitermarkus/brew,EricFromCanada/brew,Linuxbrew/brew,DomT4/brew,Linuxbrew/brew,maxim-belkin/brew,EricFromCanada/brew,konqui/brew,DomT4/brew,vitorgalvao/brew,reitermarkus/brew,Linuxbrew/brew,sjackman/homebrew,sjackman/homebrew,claui/brew,nandub/brew,mahori/brew,JCount/brew,claui/brew,maxim-belkin/brew,MikeMcQuaid/brew,reitermarkus/brew,claui/brew,mahori/brew,nandub/brew,nandub/brew,JCount/brew,DomT4/brew,maxim-belkin/brew,Homebrew/brew,mahori/brew,claui/brew,JCount/brew,EricFromCanada/brew,konqui/brew,mahori/brew,MikeMcQuaid/brew,konqui/brew,MikeMcQuaid/brew,vitorgalvao/brew,nandub/brew,Homebrew/brew,Homebrew/brew,sjackman/homebrew,Linuxbrew/brew