New comment by yopito on void-packages repository

https://github.com/void-linux/void-packages/issues/20878#issuecomment-612808426

Comment:
my bad !  
As suggested by @pullmoll : `build_wrksrc` is working perfectly fine in this case.

FTR, my `template` is now:
```
[...]
wrksrc="${_pkgname}"
build_wrksrc="sources/shiboken2"
build_style=cmake
configure_args="(args not specific to this issue)"
[...]
```

... let's close this non-issue