Fix cmake bugs

[JaeseungYeom]

Addressing issue #24

• Fix CMAKE_BINARY_DIR to CMAKE_CURRENT_BINARY_DIR
  When FetchContent builds a dependency package, the variable needed in this CMakeLists.txt is CMAKE_CURRENT_BINARY_DIR because CMAKE_BINARY_DIR points to that of the upper project.
• Remove redundant export

[rayandrew]

looks good to me, thank you @JaeseungYeom !

[hariharan-devarajan]

@JaeseungYeom that is by design to point to parent. The reason it when I have nested project more than two and added a submodules it will mess up build paths.

What is the issue this creates can you elaborate?

[JaeseungYeom]

I assume the reason you chose that is to make sure subprojects are found regardless of hierarchy of projects. That was necessary with ExternalProject_Add() which runs at build time. With ExternalProject_Add, since targets are not available at configure time, the only way to find built artifacts was to use well-known paths. external projects also had to be built in separate build steps. It is no longer necessary with FetchContent that runs at configure time. cmake processes all subprojects during configuration and their targets are immediately available. No need for a shared install location. The entire project hierarchy is built in one step with proper dependency ordering automatically handled by cmake. The benefit is that now each subproject is isolated in its own binary directory and does not pollute the parent's build directory. The updated cpp-logger builds no problem under brahma with or without dftracer and with or without dyad.
Honestly, I still do not know why pydyad was failing to build and install dftracer under spack environment. It fails with brahma. I have neither of gotcha, cpp-logger, brahma or dftracer built with spack. And still just having an activate spack environment makes it fail. So, I gave this a try and now it builds successfully.

[hariharan-devarajan]

@rayandrew can u test it a bit. The goal is all projects like DFTracer, Brahma DFTracer-utils build nicely with this change.

[rayandrew]

@JaeseungYeom @hariharan-devarajan I tested locally and it works fine.
This PR will also remove Jae-Seung's cpp-logger-fix-export.patch in this PR if merged hariharan-devarajan/brahma#52

[rayandrew]

hi @JaeseungYeom can you remove the version bumping in this PR since this is build-related issues?

Thank you!