Can not use prebuilt protobuf of parent project with cmake.

[owent]

Describe your environment
CMake, Windows

Steps to reproduce
Having a prebuilt of protobuf.

What is the expected behavior?
Do not trigger vcpkg.

What is the actual behavior?
Using vcpkg to installl protobuf again.

Additional context
Should use Protobuf_FOUND instead of protobuf_FOUND .

[ThomsonTan]

@owent if you are using a prebuilt protobuf, how about gRPC? I think gRPC will be needed for most cases when protobuf is used in this repo.

[owent]

@owent if you are using a prebuilt protobuf, how about gRPC? I think gRPC will be needed for most cases when protobuf is used in this repo.

@ThomsonTan Using -DgRPC_PROTOBUF_PROVIDER=package, and add install path to CMAKE_PREFIX_PATH or set Protobuf_DIR then we can use our prebuilt protobuf.So does other dependencies of gRPC.The document is here

I create a script toolset to build all denpendencies of gRPC.(https://github.com/atframework/cmake-toolset)
And I also build all dependencies of opentelemetry with it(except of ms-gsl, which is include by submodule instead of find_package).

The script to build opentelemetry-cpp is here

[maxgolov]

It might be different depending on what version of CMake you use. I've seen it with Gtest_FOUND and gtest_FOUND, which is different depending on whether you use newer or older package finder. Could it be something like this, can we make both checks?

[owent]

It might be different depending on what version of CMake you use. I've seen it with Gtest_FOUND and gtest_FOUND, which is different depending on whether you use newer or older package finder. Could it be something like this, can we make both checks?

Thanks, I checked the document of cmake just now and found FindProtobuf.cmake will set Protobuf_FOUND from cmake 3.6 and FindGTest.cmake will set GTest_FOUND from cmake 3.20 in the legacy MODULE mode.

I have add codes to check PROTOBUF_FOUND and use Protobuf_PROTOC_EXECUTABLE to overwrite PROTOBUF_PROTOC_EXECUTABLE when it exists. But I also found both GTEST_FOUND and GTest_FOUND are already checked.

I think the case should be the same as the package name passed into find_package, so we should use GTest_FOUND instead of gtest_FOUND and it's already the right way.