let generic_installation     ~(run_program : Machine.Make_fun.t)     ~host ~install_path     ~install_program ~witness ~url     ?unarchived_directory     ?(archive_is_directory = true)     tool_name =   let archive = Filename.basename url in   let archive_kind =     if Filename.check_suffix url "bz2" then `Tar "j"     else if Filename.check_suffix url "gz"  then `Tar "z"     else if Filename.check_suffix url "tar" then `Tar ""     else if Filename.check_suffix url "zip" then `Zip     else if Filename.check_suffix url "deb" then `Deb     else `None   in   let open KEDSL in   let unarchival =     let open Program in     let and_cd =       if archive_is_directory then         [shf "cd %s" (Option.value unarchived_directory                         ~default:(tool_name ^ "*"))]       else [] in     match archive_kind with     | `Tar tar_option ->       chain ([shf "tar xvf%s %s" tar_option archive;               shf "rm -f %s" archive; ] @ and_cd)     | `Zip ->       chain ([shf "unzip %s" archive; shf "rm -f %s" archive;] @ and_cd)     | `Deb ->       chain [         exec ["ar"; "x"; archive];         exec ["tar"; "xvfz"; "data.tar.gz"];         exec ["rm"; "-f"; "data.tar.gz"];       ]     | `None -> sh "echo Not-an-archive"   in   workflow_node     ~name:(sprintf "Install %s" tool_name)     witness     (* (single_file ~host *)     (*    (Option.value witness ~default:(install_path // tool_name))) *)     ~edges:[       on_failure_activate (rm_path ~host install_path);     ]     ~make:(       run_program         ~requirements:[           `Internet_access;           `Self_identification ["generic-instalation"; tool_name];         ]         Program.(           shf "mkdir -p %s" install_path           && shf "cd %s" install_path           && Workflow_utilities.Download.wget_program url           && unarchival           && install_program           && sh "echo Done"         ))