Currently, when git describe fails to get a git tag for the OBS Version,
a non-fatal message is printed, and the generator is left to continue,
usually ending up with a more cryptic error message down the line.
Instead, print the git output together with a short description of what
actually happened, and exit fatally so the problematic line of code is
clear. An added advantage is that the git output is printed in red
instead of (say) white on color-enabled terminals.
Include guards ensure that bootstrap includes happen only once for the
entire project. Moving all policy changes into an included file without
its own policy scope ensures that the policy is applied to the project.
OBS CMake build framework 3.0 is a minor overhaul of version 2.0. Due
to close proximity of the 2.0 rework, the amount of actual changes to
project files are minimal and mostly concern application generation.
This commit contains the bootstrap elements only and requires
OS-specific implementations to be functional.