From: David Bremner <david@tethera.net>
To: Mark Walters <markwalters1009@gmail.com>
Subject: Re: [PATCH] emacs: hello: make --batch error gracefully
In-Reply-To: <1372976299-30389-1-git-send-email-markwalters1009@gmail.com>
References: <1372976299-30389-1-git-send-email-markwalters1009@gmail.com>
User-Agent: Notmuch/0.15.2 (http://notmuchmail.org) Emacs/24.3.1
	(x86_64-pc-linux-gnu)
Date: Tue, 23 Jul 2013 23:28:11 -0300
Message-ID: <87ob9svghw.fsf@zancas.localnet>
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Cc: notmuch mailing list <notmuch@notmuchmail.org>
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Mark Walters <markwalters1009@gmail.com> writes:
> -    (call-process-region (point-min) (point-max) notmuch-command
> -			 t t nil "count" "--batch")
> +    (unless (= (call-process-region (point-min) (point-max) notmuch-command
> +				    t t nil "count" "--batch") 0)
> +      (notmuch-logged-error "notmuch CLI version mismatch error (count --batch)
> +The most likely cause of this error is that the CLI is too old
> +to support count --batch and needs to be upgraded to the same
> +version as notmuch-emacs"))
> +

I had a look at this, and I agree the current failure mode is not nice
(it just says something mysterious about nil not being a string). On the
other hand, I think we should use the two argument form of
notmuch-logged-error, and the the first argument should say only what we
know. Something like

(notmuch-logged-error "notmuch count --batch failed"
"notmuch count --batch failed
Please check that the notmuch CLI is new enough to  support `count
--batch'. In general we recommend running matching versions of the CLI
and emacs interface.")

d