correct prefix in package-config file

[Andreas Dedner]

Hi, I'm a new user of scikit-build and it's been extremely useful. We have a large number of interconnected C++/python projects which we would like to package - so thanks for the great work you have done here!

Everything works like a charm except for one issue I haven't figured out how to solve:

we use pkg-config to locate already installed components of our project (so an incremental install is supposed to be possible). We have a 'package.pc.in' file in our cmake source directory containing the line 'prefix=CMAKE_INSTALL_PREFIX'. After the wheel is build the resulting 'packag.pc' file contains something like

'prefix=/tmp/pip-install-8q9cu4wj/package/_skbuild/linux-x86_64-3.8/cmake-install`

and that's put into the virtualenv (~/python-evn/lib/pkgconfig'.

Extracting that with 'pkg-config' fails obviously. I probably need to correct that during installation of the wheel because the correct path (i.e. ~/python-env') is not know during the build of the wheel.

Any help would be greatly appreciated

Andreas