[janbernloehr]

What does this PR do ?

Fixes Linux x86_64 installation on Python 3.14 by selecting pynini==2.1.7, while retaining pynini==2.1.6.post1 on Python versions below 3.14.

Fixes #530.

The unconditional 2.1.6.post1 pin forces Python 3.14 installations to build Pynini from source because that release has no compatible wheel. Without OpenFst development headers, the build fails with fst/util.h: No such file or directory. Pynini 2.1.7 provides a CPython 3.14 Linux x86_64 wheel.

Apply the same mutually exclusive environment markers to requirements/requirements.txt and requirements/requirements_test.txt, so installing the test or all extra does not reintroduce the incompatible pin.

Packaging verification

Manually resolved the Pynini entries extracted from each changed requirements file against public PyPI, targeting x86_64-manylinux_2_28 with source builds disabled:

Target Python	Runtime requirements	Test requirements
3.9, 3.10, 3.11, 3.12, 3.13	2.1.6.post1	2.1.6.post1
3.14	2.1.7	2.1.7

The unpatched pynini==2.1.6.post1 requirement fails the same Python 3.14 check with “no usable wheels.” The built package's Requires-Dist metadata preserves both markers for the runtime dependencies and the test and all extras.

To reproduce the resolver check from the patched checkout:

for requirements in requirements/requirements.txt requirements/requirements_test.txt; do
  for version in 3.9 3.10 3.11 3.12 3.13 3.14; do
    grep '^pynini' "$requirements" | uv pip compile - \
      --python-version "$version" \
      --python-platform x86_64-manylinux_2_28 \
      --only-binary :all:
  done
done

These checks isolate the dependency being changed; they are not full dependency-install or grammar-suite runs. The Python 3.14 Linux installation and English normalization smoke test reported in #530 used the same patch on r1.2.0; that runtime test was not repeated on this branch. Python versions after 3.14 and other platforms are unverified.

If #474 lands first, the markers need to move into its pyproject.toml runtime dependencies and test extra.

Before your PR is "Ready for review"

Pre checks:

• Have you signed your commits? Use git commit -s to sign. — Commit includes a Signed-off-by trailer.
• Do all unittests finish successfully before sending PR? — Not run on this branch; retain draft status.
  1. pytest or (if your machine does not have GPU) pytest --cpu from the root folder (given you marked your test cases accordingly @pytest.mark.run_only_on('CPU')).
  2. Sparrowhawk tests bash tools/text_processing_deployment/export_grammars.sh --MODE=test ...
• If you are adding a new feature: Have you added test cases for both pytest and Sparrowhawk here. — N/A: dependency compatibility fix; no grammar changes.
• Have you added __init__.py for every folder and subfolder, including data folder which has .TSV files? — N/A: no new folders.
• Have you followed codeQL results and removed unused variables and imports (report is at the bottom of the PR in github review box) ? — Pending PR checks.
• Have you added the correct license header Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved. to all newly added Python files? — N/A: no Python files added.
• If you copied nemo_text_processing/text_normalization/en/graph_utils.py your header's second line should be Copyright 2015 and onwards Google, Inc.. See an example here. — N/A: no copied code.
• Remove import guards (try import: ... except: ...) if not already done. — N/A: no imports changed.
• If you added a new language or a new feature please update the NeMo documentation (lives in different repo). — N/A: no new language or feature.
• Have you added your language support to tools/text_processing_deployment/pynini_export.py. — N/A: no new language.

PR Type:

• New Feature
• Bugfix
• Documentation
• Test

If you haven't finished some of the above items you can still open "Draft" PR.

Prepared with assistance from OpenAI Codex (GPT-6).