-Dprotobuf_ABSL_PROVIDER="package" not fully functional yet

[h-vetinari]

Between 21.12 and 22.0, protobuf gained a dependence on abseil, including a possibility to use -Dprotobuf_ABSL_PROVIDER="package".

However, adding that to a CMake build invocation does not yet work (from conda-forge/libprotobuf-feedstock#144):

CMake Error at cmake/libprotobuf-lite.cmake:26 (target_link_libraries):
  Target "libprotobuf-lite" links to:

    absl::absl_check

  but the target was not found.  Possible reasons include:

Presumably some places need a find_package(absl REQUIRED) behind an if-statement.

[mkruskal-google]

This sounds like you have an older version of Abseil installed on your machine. We require at least https://github.com/abseil/abseil-cpp/releases/tag/20230125.0

[adamjstewart]

Where is this version requirement documented?

[mkruskal-google]

Our protobuf_deps.bzl file is the SOT for our dependencies

[adamjstewart]

Does it have to be that exact commit or can it be a range of versions?

[mkruskal-google]

That commit corresponds to the 20230125.2 release. Anything later than that is likely to work, but if it's not an LTS release then Abseil's cmake install will be disabled. This will result in our install setup being broken without some extra cmake flags to bypass it

[adamjstewart]

This "protobuf only supports one version of abseil-cpp" thing is getting tricky to manage. The latest release of onnxruntime requires protobuf, but it also requires abseil-cpp 20240116.0+. But the latest release of protobuf requires abseil-cpp 20230802.1. Does that mean that it isn't possible to install the latest version of onnxruntime? Or that everyone should just figure out their own range of compatible versions?