Demi Marie Obenour <demiobenour@gmail.com> writes:

> On 11/8/25 17:14, Alyssa Ross wrote:
>> Alyssa Ross <hi@alyssa.is> writes:
>> 
>>> Demi Marie Obenour <demiobenour@gmail.com> writes:
>>>
>>>> On 11/8/25 14:49, Alyssa Ross wrote:
>>>>> Demi Marie Obenour <demiobenour@gmail.com> writes:
>>>>>
>>>>>> @@ -113,14 +76,15 @@ let
>>>>>>  
>>>>>>    kernel = linux_latest;
>>>>>>  
>>>>>> -  appvm = callSpectrumPackage ../../img/app { inherit (foot) terminfo; };
>>>>>> -  netvm = callSpectrumPackage ../../vm/sys/net { inherit (foot) terminfo; };
>>>>>> +  appvm = callSpectrumPackage ../../img/app { inherit (no_pgo_foot) terminfo; };
>>>>>> +  netvm = callSpectrumPackage ../../vm/sys/net { inherit (no_pgo_foot) terminfo; };
>>>>>>  
>>>>>>    # Packages that should be fully linked into /usr,
>>>>>>    # (not just their bin/* files).
>>>>>>    usrPackages = [
>>>>>> -    appvm kernel.modules firmware netvm
>>>>>> -  ] ++ (with pkgsGui; [ mesa dejavu_fonts westonLite ]);
>>>>>> +    appvm kernel.modules firmware kmod kmod.lib
>>>>>> +    netvm mesa dejavu_fonts westonLite
>>>>>> +  ];
>>>>>>  
>>>>>>    appvms = {
>>>>>>      appvm-firefox = callSpectrumPackage ../../vm/app/firefox.nix {};
>>>>>
>>>>> So based on what we'd discussed previously, I was ready to just apply
>>>>> this and pare down the Nix changes myself since I don't have to worry
>>>>> about rebuilds, etc., but in doing so I came across this.  Do you know
>>>>> why kmod.lib is required?  Is something impurely dlopening it?  Seems
>>>>> very strange, but I did verify that it's required for Weston to start.
>>>>
>>>> systemd uses dlopen heavily.  This allows dependencies to be optional
>>>> at runtime.  I remember strace showing that systemd-udevd dlopen's
>>>> kmod.lib.  In short, your diagnosis is correct.
>>>
>>> Okay, that's a packaging bug in Nixpkgs then.  (See e.g. [1].)  I'll see
>>> what can be done.
>>>
>>> [1]: https://github.com/NixOS/nixpkgs/commit/2328731ad041735a2260698574ce6599591f33ad
>> 
>> I have looked into it a bit and am now even more confused.  From what I
>> can see, loading libkmod should be done by libsystemd-shared.so, which
>> has kmod.lib in its RUNPATH.
>
> According to https://wiki.debian.org/RpathIssue, only the RUNPATH of
> the executable is honored.  The RUNPATH of libraries is not honored.
> For this to work, libsystemd-shared.so needs to have kmod.lib in its
> RPATH, and udevadm *may* need to not have a RUNPATH.

Right, so we might need to add --force-rpath to the patchelf invocation.

I wonder why this doesn't affect every NixOS system, though.  They
certainly don't have /usr/lib/libkmod.so.2.