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

[Adam Dinwoodie <adam@dinwoodie.org>]

On Tue, Feb 01, 2022 at 04:53:47PM +0000, Jon Turney wrote:
> 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'?

...yes, that would in fact work, and is clear.

> >      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.

Ah, okay.  I think I hit this with `-M` and assumed -- evidently
incorrectly -- that the same behaviour would exist for `-q`.  I agree
the current text is entirely accurate for the fully non-interactive
mode.

I think this caught me out because I frequently run with `-M` -- I don't
care about most of the options, but I do want to see what packages are
about to be updated -- and I almost never want to use the download-only
or install-only modes.  But I used `-L` as a one-off when I was
uninstalling and reinstalling a bunch of packages and didn't want to hit
the network every time, then forgot about it.  And it wasn't until I was
musing about the fact that I hadn't seen any package updates for a few
weeks when trying to do my regular updates with `-M` that I realised
what had happened...

Given all that, I think everything seems sensible except for the fact
that `-M` doesn't follow the same behaviour as `-q`.

> > 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).

I definitely see no harm in that approach, and I agreed that'd make
things clearer again.  But, as above, I think the key thing from my
perspective would be for `-M` and `-q` to have consistent behaviour.