Confusion on alternatives for /usr/lib/xorg/modules/linux/libglx.so

[Hualet Wang]

Thanks for your explanation, Andreas. But I still get further questions 
here:


On 7/16/18 4:26 AM, Andreas Beckmann wrote:
> On 2018-07-15 09:00, Hualet Wang wrote:
>> Hi, Debian NVIDIA Maintainers
>>
>> Recently I’m trying port nvidia-prime to our distribution,
> We might be interested in the result of that project.
> https://bugs.debian.org/875959
The progress seems to be very slow?
>> deepin which is a Debian Sid derivative, during the process I found that users with nvidia-dirver installed, some of them got /usr/lib/xorg/modules/linux/libglx.so and some of them didn’t, and among the users who got /usr/lib/xorg/modules/linux/libglx.so, some of their X load that file when LoadModule glx happens, and the others just load /usr/lib/xorg/modules/extensions/libglx.so.
> This should be fixed wth 390.67-2.
We're now on 390.59-2, but we seem to still get this problem, I'll dig 
into it.
>> I checked postinst script of glx-alternative-nvidia, and see it "handles alternatives for /usr/lib/xorg/modules/linux/libglx.so”.
>>
>> So I’m totally confused:
>> [1] why there’s an alternatives for /usr/lib/xorg/modules/linux/libglx.so ?
> NVIDIA provides their own libglx.so xorg module. You need that instead
> of the standard Xorg one if you use the nvidia driver in Xorg (but not
> in e.g. bumblebee setups)
>
> Historically we placed it in linux/ since that path was prepended to the
> search path (up to Xserver 1.19) and the module was found there (if the
> slave alternative put it there). With Xserver 1.20+ we need to manually
> set the search path in the Xorg config to achieve this (done since
> 390.67-1).
I'm wondering which part of code or scripts doing this "manual" work?  
So I can try to debug the problem on my own :)
>> [2] how the nvidia-driver suppose to change the behavior that which libglx.so is loaded ?
> It will not work (efficently) if the wrong one is loaded.
>
>
> Feel free to ask more questions.
>
>
> Andreas
Thank you for your time again :)