setup-*.exe --help default explanation re -D/-L options [Was: [ANNOUNCEMENT] Updated: setup (2.917)]

[Jon Turney]

On 31/01/2022 22:11, Adam Dinwoodie wrote:
> On  Mon, 31 Jan 2022 12:56:13 -0700, Brian Inglis wrote:
>> On 2022-01-31 08:46, Andrey Repin wrote:
>>> Greetings, Jon Turney!
>>>
>>>> Probably what's wanted is to remember the state of those checkboxes, if
>>>> this isn't the first time setup has been run?
>>>
>>> That's a feature silently longed for for a loong time. :) But this is such a
>>> low priority, very few people actually mentioned it in the past years.
>>
>> It could usefully be added similarly to last-action:
>>
>> 	$ fgrep -A1 action /etc/setup/setup.rc
>> 	last-action
>> 		Download,Install
>>
>> last-shortcut:
>> 	Desktop|StartMenu|none,...
> 
> This reminded me of a bug report I've been meaning to properly
> characterise and report for a while, and also pointed me at a
> workaround...
> 
> Currently, running `setup-*.exe --help` produces output that includes
> the following:
> 
>      -D --download       Download packages from internet only
>      -L --local-install  Install packages from local directory only
> 
>      The default is to both download and install packages, unless either
>      --download or --local-install is specified.
> 
> I think the descriptions for the `-D` and `-L` options are misleading,
> at least in combination with that final line, which is definitely wrong.
> As I understand it, the actual behaviour would be better described by
> something like the below:
> 
>      -D --download       Download packages from internet only, unless -L
>                          is also specified
>      -L --local-install  Install packages from local directory only,
>                          unless -D is also specified

One could just remove the word 'only'?

> 
>      If neither --download nor --local-install is specified, the default
>      is to repeat the same action as from the previous run.  If no
>      previous run can be found, the default is to perform both actions,
>      and both actions can be explicitly requested by specifying both
>      --download and --local-install.

Note that I tweaked the behaviour of this a bit in [1]

[1] 
https://cygwin.com/git/?p=cygwin-apps/setup.git;a=commit;h=147fc15d0222e050779b18a209991c258d85944f

I think that makes the current help text accurately describe 
non-interactive mode.

There are some cases in interactive mode which are obscure (e.g. '-M' 
without '-D' or '-L' gets you whatever mode you used last time without 
showing you what it was, but I'm not sure if that needs to be here.

> In particular, the fact that the two options currently say they will
> "only" do their action, and that the default is to perform both, lead me
> to believe (a) the options were mutually exclusive and one would
> presumably override the other, (b) this was probably a legacy from
> before setup.rc stored the previous action, and therefore (c) if I was
> running setup with `-q` or `-M`, there was no way to get the supposedly
> default "do both" behaviour; I'd instead need to go through the full
> GUI.
> 
> Having now seen how this setting is stored, I've realised I can just
> call setup with `-DL` and it'll perform both actions again.  But I think
> my assumption that "default" was supposed to mean "default always" not
> "default only on first run" wasn't *entirely* PEBCAK (even if it mostly
> was), so that help text would definitely benefit from being made a bit
> more explicit.
> 
> (I'm aware my suggestion above is decidedly wordy; it's not intended to
> be exactly what I think is required, only a first pass at clarifying the
> key details I think are missing.)

Perhaps the best thing would be to have something like 
'--mode={download, install, somebetterwordforboth}' and document '-D' 
and '-L' as short aliases for forms of that (which makes the modality 
clear).