onnx 1.21.0 upgrade: fix IR version 13 incompatibility with onnxruntime

[timenick]

Problem

PR #223 bumps onnx from 1.18 to 1.21.0. CI fails with 63+ test failures across test (analyze) and test (optim) jobs.

Root cause

onnx 1.21.0 changed helper.make_model() to default ir_version to 13 (was 8/9 in 1.18). onnxruntime only supports up to IR version 11, so any code path that creates a model and runs it through ORT fails with:

Unsupported model IR version: 13, max supported IR version: 11

CI failures

test (optim) — 3 failures

• tests/unit/optim/fusions/test_fusion_rmsnorm.py — TestNumericEquivalence (3 tests)
• 5 make_model() calls without ir_version set (lines 70, 121, 265, 304, 340)

test (analyze) — 60+ failures

• tests/unit/analyze/test_input_generators.py — test_operator_validation for all opsets (17, 22, 23)
• Root: src/winml/modelkit/pattern/op_input_gen/op_input_gen.py:1017 — _create_model() has no ir_version set
• validate_inputs() → _run_op_on_cpu() creates ORT session → IR version 13 rejected

Fix needed

Add model.ir_version = 11 (or 8 for tests) after make_model() in these locations:

Source code (2 files):

File	Line
src/winml/modelkit/pattern/op_input_gen/op_input_gen.py	1017
src/winml/modelkit/analyze/core/runtime_checker_query.py	1120

Test code (1 file):

File	Lines
tests/unit/optim/fusions/test_fusion_rmsnorm.py	70, 121, 265, 304, 340

Note: 80+ other test files also have make_model() without ir_version, but don't currently fail because they don't run ORT inference. Consider a sweep to future-proof.

Related

• PR build(deps): bump onnx from 1.18 to 1.21.0 #223 (dependabot/pip/onnx-1.21.0)

[timenick]

ORT support for IR version 13

Current status: ORT does not yet support IR version 13.

• Our onnxruntime-windowsml>=1.23.2 supports up to IR version 11
• Latest ORT 1.24.4 (2026-03-17) compatibility table tops out at ONNX 1.16.1 / IR version 10
• ORT integration for ONNX 1.21.0 is in progress: ONNX 1.21.0 integration onnxruntime#27601 (status OPEN, last updated 2026-04-02)
• That PR upgrades ORT to support opset 26 + IR version 13, expected to ship with ORT 1.25

Impact

Until ORT 1.25 ships, upgrading onnx to 1.21.0 requires explicitly setting model.ir_version = 11 (or lower) after every make_model() call, otherwise ORT cannot load the model.

🤖 Generated with Claude Code

[DingmaomaoBJTU]

Triage summary

• Component: Repository
• Priority: P1
• Owner(s): @timenick @KayMKM

onnx 1.21.0 upgrade (PR #223) causes 63+ CI test failures because the new default IR version 13 exceeds onnxruntime's max supported IR version 11; fix by setting ir_version=11 after make_model() in the affected source and test files.