[Qbs] Using ConanfileProbe with yocto cross compiling toolchain

[Richard Weickelt]

> I will try this approach. But maybe I use `conan install -e` instead of
> setting the environment variables for the complete process.

If the result is the same, then why not.

> Do you know how I can easily extract the environment variables?
>  https://doc.qt.io/qbs/jsextension-environment.html#currentenv  seems like a
> solution but I don't know how to access a process environment with this.

Which environment variables? If I understood you correctly, then you have
environment variables generated by yocto in a file/script which you need to
parse somehow in a probe. There is no probe for that, you would have to
implement your own.

If the environment variables are already in the environment when calling qbs
resolve (for instance by sourcing the script in the shell), then
ConanfileProbe should already have them.