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Subject: Re: libsensors soname bump
To: Jean Delvare <jdelvare@suse.de>
Cc: linux-hwmon@vger.kernel.org
References: <20181216124344.49d06b69@endymion>
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Date: Mon, 17 Dec 2018 10:46:43 +0100
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Hi Jean,

On 16. 12. 18 12:43, Jean Delvare wrote:
> Hi Ondřej,
> 
> You have recently released lm-sensors 3.5.0 with a new soname for
> libsensors:
> 
> -LIBMAINVER := 4
> -LIBMINORVER := 4.0
> +LIBMAINVER := 5
> +LIBMINORVER := 0.0
> 
> -#define SENSORS_API_VERSION            0x440
> +#define SENSORS_API_VERSION            0x500
> 
> This is declaring the new library as incompatible with the previous
> version, meaning that distributions will have to build and ship both
> libsensors4 and libsensors5 for a long time until all applications have
> been updated and rebuilt to link with the new library. This is a
> significant effort for the whole community and should only be done when
> necessary.

I thought there was an ABI change, which would warrant a soname bump. Or
am I wrong in thinking that? I was mistaken however and I'm sorry about
that, there was no ABI change.

I don't see why distributions would have to ship two versions of the
library. The *name* of the library didn't change, it's still libsensors
(not libsensors4 or libsensors5).
[~/git/lm-sensors]$ make
...
[~/git/lm-sensors]$ ls lib/ | grep libsensors.so
libsensors.so
libsensors.so.5
libsensors.so.5.0.0

So all distros need to do is rebuild dependent packages. No changes to
other packages should be required.

Am I missing something?

Thanks.

Ondra

> 
> In this specific case, I can't see what warranted such a change of
> major library version change. From
> lm-sensors/doc/developers/release_checklist:
> 
>   Remember: update main number when interface changes, minor if new
>   functionality is added, and patch if only bugs are fixed.
> 
> In this case I can only see new functionality added, there is no
> interface change. Therefore the correct value for SENSORS_API_VERSION
> was 0x450, not 0x500. This would avoid the parallel maintenance and
> installation of 2 versions of the library for several years to come.
> 
> Would you consider quickly releasing lm-sensors 3.5.1 with the proper
> library version number, to save all that work to all application
> authors/maintainers and distribution package maintainers?
> 
> Thanks,
>