[tmva][sofie] Require onnx>=1.19.1 for tests

In commit 178a9f9, I activated several SOFIE tests by moving the SOFIE
PyTorch and Keras parsers out of `tmva/pymva`, because SOFIE and PyMVA
are unrelated and we lost test coverage for these SOFIE parsers, because
`tmva-pymva` is always disabled.

But as reported in #20571, we now see SOFIE test failures on macOS
because `torch.onnx` implicitly required `onnx>=1.19.1`, although this
is not part of the `torch` dependencies as `onnx` support is optional.
However, `onnx>=1.19.1` can't be installed on macOS because the
transient update of `ml_dtypes` is conflicting with the current version
of the `tensorflow` package.

To get out of this, we have to check `onnx>=1.19.1` ourselves and
disable some tests if the version is older. This is the solution with
the least test coverage regression. There is even no coverage regression
at all, if you compare to the state before 178a9f9 a few days ago.

We should also consider to require `onnx>=1.19.1` in our
`requirements.txt` in the future, so our users don't face similar
trouble from exporting PyTorch models to onnx. But this should only be
done once we are sure that it can also be installed on macOS without
breaking something else.

Closes #20571.

Author: guitargeek

tmva/sofie/test/CMakeLists.txt

@@ -108,8 +108,36 @@ endif()
 # Look for needed Python modules
 ROOT_FIND_PYTHON_MODULE(torch)
 ROOT_FIND_PYTHON_MODULE(keras)
+ROOT_FIND_PYTHON_MODULE(onnx)
 
-if (ROOT_TORCH_FOUND)
+
+# Some tests need to be disabled when the onnx version is too low, because then
+# onnx is not compatible with PyTorch. This is not encoded in the PyTorch
+# dependency resolution, because onnx is an optional dependency of PyTorch. So
+# we have to take care of onnx version checks ourselves. See also:
+# https://github.com/root-project/root/issues/20571
+#
+# TODO: We can't enforce this minimum onnx version in the global
+# requirements.txt yet, because the transient update of ml_dtypes is
+# conflicting with the current version of the tensorflow package on the macOS
+# runners. Once we have installed onnx>=1.19.1 on all of our CI nodes that
+# install onnx, we should also consider requiring this minimum version from our
+# users, se they don't face bad surprises when exporting PyTorch models to
+# onnx.
+set(minimum_onnx_version "1.19.1")
+if (NOT ROOT_ONNX_FOUND)
+  set(minimum_onnx_found FALSE)
+elseif (NOT DEFINED ROOT_ONNX_VERSION)
+  message(WARNING "onnx found, but version unknown — cannot verify compatibility.")
+  set(minimum_onnx_found TRUE) # In this case we assume it is of the right version
+elseif (ROOT_ONNX_VERSION VERSION_LESS ${minimum_onnx_version})
+  message(WARNING "onnx version ${ROOT_ONNX_VERSION} found, but we only support onnx>=${minimum_onnx_version} for compatibility reasons. Some TMVA-SOFIE tests will be disabled.")
+  set(minimum_onnx_found FALSE)
+else()
+  set(minimum_onnx_found TRUE)
+endif()
+
+if (minimum_onnx_found AND ROOT_TORCH_FOUND)
   configure_file(Conv1dModelGenerator.py  Conv1dModelGenerator.py COPYONLY)
   configure_file(Conv2dModelGenerator.py  Conv2dModelGenerator.py COPYONLY)
   configure_file(Conv3dModelGenerator.py  Conv3dModelGenerator.py COPYONLY)
@@ -129,8 +157,8 @@ if (ROOT_TORCH_FOUND)
   endif()
 endif()
 
-# Any reatures that link against libpython are disabled if built with tpython=OFF
-if (tpython AND ROOT_TORCH_FOUND AND BLAS_FOUND)
+# Any features that link against libpython are disabled if built with tpython=OFF
+if (minimum_onnx_found AND tpython AND ROOT_TORCH_FOUND AND BLAS_FOUND)
   configure_file(generatePyTorchModelClassification.py generatePyTorchModelClassification.py COPYONLY)
   configure_file(generatePyTorchModelMulticlass.py generatePyTorchModelMulticlass.py COPYONLY)
   configure_file(generatePyTorchModelRegression.py generatePyTorchModelRegression.py COPYONLY)
@@ -151,7 +179,7 @@ if (tpython AND ROOT_TORCH_FOUND AND BLAS_FOUND)
 endif()
 
 
-# Any reatures that link against libpython are disabled if built with tpython=OFF
+# Any features that link against libpython are disabled if built with tpython=OFF
 if (tpython AND ROOT_KERAS_FOUND AND BLAS_FOUND)
 
   set(unsupported_keras_version "3.10.0")