[bug#28765] [PATCH] config: Conditionally configure daemon offload script.

[ludo@gnu.org (Ludovic Courtès)]

Hello,

Eric Bavier <ericbavier@centurylink.net> skribis:

> On Mon, 09 Oct 2017 23:07:10 +0200
> ludo@gnu.org (Ludovic Courtès) wrote:
>
>> Eric Bavier <bavier@cray.com> skribis:
>> 
>> > From 984e324370c2c17d8d1a982adf2884112c9e64b7 Mon Sep 17 00:00:00 2001
>> > From: Eric Bavier <bavier@cray.com>
>> > Date: Mon, 9 Oct 2017 13:58:04 -0500
>> > Subject: [PATCH] config: Conditionally configure daemon offload script.  
>>                    ^
>> Nitpick: rather “build:”, which is for all things build-related.
>> 
>> > * config-daemon.ac (nix/scripts/offload): Configure only if offloading enabled.  
>> 
>> It LGTM, but is it helpful?  guix-daemon does not invoke ‘guix offload’
>> when it’s missing, as can be seen in guix-daemon.cc:
>> 
>>   #ifdef HAVE_DAEMON_OFFLOAD_HOOK
>>         /* Use our build hook for distributed builds by default.  */
>>   …
>
> Or maybe something like this would be preferable, to avoid exporting
> NIX_BUILD_HOOK if Guix has been configured to disable the daemon
> offload hook?
>
> --- a/build-aux/pre-inst-env.in
> +++ b/build-aux/pre-inst-env.in
> @@ -50,13 +50,9 @@ NIX_LIBEXEC_DIR="@abs_top_builddir@/nix/scripts" # for 'guix-authenticate'
>  export NIX_ROOT_FINDER NIX_SUBSTITUTERS NIX_LIBEXEC_DIR
>  
>  NIX_BUILD_HOOK="$abs_top_builddir/nix/scripts/offload"
> -if [ -x "$NIX_BUILD_HOOK" ]
> -then
> -    export NIX_BUILD_HOOK
> -else
> -    # No offloading support.
> -    unset NIX_BUILD_HOOK
> -fi
> +@BUILD_DAEMON_OFFLOAD_TRUE@export NIX_BUILD_HOOK
> +@BUILD_DAEMON_OFFLOAD_FALSE@# No offloading support.
> +@BUILD_DAEMON_OFFLOAD_FALSE@unset NIX_BUILD_HOOK

It’s nicer (you’re welcome to push this change!), but it’s equivalent to
what’s already here, no?

Is there a problem that we are trying to solve in the first place, or is
it more about making things nicer?

Thank you,
Ludo’.