FHS 3.0 contains the sections below regarding `/var/run` [1].

> 5.13. /var/run : Run-time variable data
> ---------------------------------------
>
> ### 5.13.1. Purpose ###
>
> This directory was once intended for system information data
> describing the system since it was booted. These functions have been
> moved to /run; this directory exists to ensure compatibility with
> systems and software using an older version of this specification.

And, for `/run` [2]:

> 3.15. /run : Run-time variable data
> -----------------------------------
>
> ### 3.15.1. Purpose ###
>
> The purposes of this directory were once served by /var/run. In
> general, programs may continue to use /var/run to fulfill the
> requirements set out for /run for the purposes of backwards
> compatibility. Programs which have migrated to use /run should cease
> their usage of /var/run, except as noted in the section on /var/run.

So, it’d be great if the configure script, would use `/run` as the parent directory, if it’s present.
[1] https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.html#varrunRuntimeVariableData
[2] https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.html#runRuntimeVariableData