Subject: Re: [bug#47768] [PATCH 04/37] gnu: ocaml-lwt: Make libev a propagated input.

From: pukkamustard <[email-masked]>
Date: Tue, 20 Apr 2021 05:54:56 +0000

Hi Maxime,

Thanks for your review!

Maxime Devos <[email-masked]> writes:

> On Wed, 2021-04-14 at 11:12 +0200, pukkamustard wrote:
>> * gnu/packages/ocaml.scm (ocaml-lwt) [propagated-inputs]: Add 
>> libev.
>>   [inputs]: Remove libev.
>>   (ocaml-ouint2, ocaml4.07-lambda-term, ocaml-markup) [inputs]: 
>>   Remove libev.
>> ---
>
> What's the reason libev has been moved from inputs to 
> propagated-inputs?
>

As far as I understand libev is a runtime/build time dependency of 
lwt.

Before this patch it was necessary for packages using lwt to also 
add
libev as input (e.g. ocaml4.07-lambda-term or ocaml-markup). This 
was
even worse when using lwt indirectly (e.g. by including 
ocaml-markup
somewhere): build would fail but it was not clear what needs to be 
done
as lwt was not directly included as input (but as propagated-input 
of
ocaml-markup).

Adding libev as propagate-input makes packages using lwt "just 
work".

-pukkamustard