Re: [PATCH] switch: mention the --detach option when dying due to lack of a branch

[Junio C Hamano <gitster@pobox.com>]

Alex Henrie <alexhenrie24@gmail.com> writes:

> Users who are accustomed to doing `git checkout <tag>` assume that
> `git switch <tag>` will do the same thing. Inform them of the --detach
> option so they aren't left wondering why `git switch` doesn't work but
> `git checkout` does.

An error message certainly would help over showing

	fatal: a branch is expected, got tag 'abc'

but I have to wonder why we shouldn't DWIM and detach the HEAD at
the commit the user wanted to.  That would also solve the issue of
leaving them wondering why switch is broken and checkout is not, no?

If the advice for detached HEAD state is enabled, then the user will
be reminded that they are not on any branch the usual way when the
HEAD is detached at the named commit.  And if the advice is not
enabled, then they will not be helped by this new advise() message
we add here.

> +	if (advice_enabled(ADVICE_DETACHED_HEAD))
> +		advise(_("The specified commit is not a local branch.\n"
> +			 "If you want to enter detached head mode, try again with the --detach option."));
> +

"detached HEAD" is a state, and not a mode.

s/enter detached head mode/detach HEAD at the commit/ perhaps.

Thanks.