find_package(Vix) fails due to missing Boost::system / Boost::filesystem

[GaspardKirira]

Description

When using find_package(Vix CONFIG REQUIRED) in a downstream project, CMake fails with errors such as:

The link interface of target "vix::core" contains:
  Boost::filesystem
but the target was not found

or:

Boost::system target missing
This happens even when Boost is installed on the system.

Root cause
VixTargets.cmake was included before resolving required dependencies.
Boost targets (Boost::system, Boost::filesystem) were referenced in exported link interfaces without being guaranteed to exist.
Deprecated FindBoost behavior caused additional issues on macOS (CMP0167).

Affected platforms
macOS (Homebrew + AppleClang)

Linux (CMake ≥ 3.20)

Fix
Ensure all dependencies are resolved before loading VixTargets.cmake.
Prefer Boost CONFIG mode on modern CMake.
Remove unnecessary Boost::filesystem leakage from public APIs.

Status
✅ Fixed in v1.17.4