
Andrew Stewart engineered and maintained core data science and machine learning packaging infrastructure across the spack/spack and spack/spack-packages repositories. He delivered coordinated upgrades to Python libraries such as NumPy, PyTorch, and SciPy, modernizing dependency management and improving build reliability for downstream users. His work included resolving complex compatibility issues, refining build systems with CMake and Python, and implementing robust CI/CD workflows. Stewart also contributed to cross-repo policy updates, deprecation handling, and technical documentation, ensuring reproducible environments and streamlined onboarding. His technical depth is reflected in careful code refactoring, type hinting, and platform-specific fixes that reduced maintenance overhead and improved stability.

In Oct 2025, the developer contributed across Spack's ecosystem to remove deprecated components, modernize CI for ML workflows, and strengthen package maintenance. Key outcomes include deprecation removals across I-L, libxml2, and OpenSSL; an updated ML CI image with Clang-based builds for TensorFlow/JAX; a simplified dependency graph by removing the optional mypy pin from py-charset-normalizer; expansion of packaging coverage with new/updated core Python packages and a new package py-pypinfo; cross-project dependency upgrades to improve security and compatibility; and a grammar fix in the Spack Audit Module to improve clarity. These efforts reduce maintenance burden, accelerate ML workflows, and improve overall ecosystem reliability for downstream users.
In Oct 2025, the developer contributed across Spack's ecosystem to remove deprecated components, modernize CI for ML workflows, and strengthen package maintenance. Key outcomes include deprecation removals across I-L, libxml2, and OpenSSL; an updated ML CI image with Clang-based builds for TensorFlow/JAX; a simplified dependency graph by removing the optional mypy pin from py-charset-normalizer; expansion of packaging coverage with new/updated core Python packages and a new package py-pypinfo; cross-project dependency upgrades to improve security and compatibility; and a grammar fix in the Spack Audit Module to improve clarity. These efforts reduce maintenance burden, accelerate ML workflows, and improve overall ecosystem reliability for downstream users.
September 2025 highlights: Delivered extensive library upgrades and API modernization across core repositories, driving stability, compatibility, and faster downstream adoption. Key features include major version bumps across spack-packages (py-lightning, py-matplotlib, py-numpy, py-scipy, GDAL, py-geemap, py-shapely, py-ruff, PDAL, and more) and new package additions, along with targeted deprecations to modernize the API surface. Major fixes addressed build stability and compatibility issues (lzo revert; py-torchgeo minimum rasterio version; SMP dependency), complemented by build-system hygiene (meson-python and scipy constraints) and compliance improvements (IBM/terratorch licensing). Overall impact: improved dependency hygiene, reduced maintenance burden, and clearer upgrade paths for downstream users.
September 2025 highlights: Delivered extensive library upgrades and API modernization across core repositories, driving stability, compatibility, and faster downstream adoption. Key features include major version bumps across spack-packages (py-lightning, py-matplotlib, py-numpy, py-scipy, GDAL, py-geemap, py-shapely, py-ruff, PDAL, and more) and new package additions, along with targeted deprecations to modernize the API surface. Major fixes addressed build stability and compatibility issues (lzo revert; py-torchgeo minimum rasterio version; SMP dependency), complemented by build-system hygiene (meson-python and scipy constraints) and compliance improvements (IBM/terratorch licensing). Overall impact: improved dependency hygiene, reduced maintenance burden, and clearer upgrade paths for downstream users.
In August 2025, delivered extensive packaging updates and stability improvements across spack-spack-packages, ROCm/pytorch, and spack. The work enabled broader workload support, up-to-date dependencies, and more reliable builds. Targeted fixes improved build paths, compiler handling, and formatting/consistency, reducing maintenance burden and downstream risk. Demonstrated strong cross-repo collaboration and alignment with long-term maintenance goals for critical scientific software stacks.
In August 2025, delivered extensive packaging updates and stability improvements across spack-spack-packages, ROCm/pytorch, and spack. The work enabled broader workload support, up-to-date dependencies, and more reliable builds. Targeted fixes improved build paths, compiler handling, and formatting/consistency, reducing maintenance burden and downstream risk. Demonstrated strong cross-repo collaboration and alignment with long-term maintenance goals for critical scientific software stacks.
July 2025 (2025-07) performance summary for spack/spack-packages focusing on delivering a modernized data science stack, enhanced geospatial tooling, and hardened toolchain compatibility. The work enabled faster feature adoption, improved security posture, and more reliable builds across modern CI and runtime environments.
July 2025 (2025-07) performance summary for spack/spack-packages focusing on delivering a modernized data science stack, enhanced geospatial tooling, and hardened toolchain compatibility. The work enabled faster feature adoption, improved security posture, and more reliable builds across modern CI and runtime environments.
June 2025 performance highlights: Delivered a comprehensive ML/data-science stack upgrade across the spack-packages and core Spack repositories, stabilized build/test workflows, and enhanced developer tooling. Implemented forward-compatible updates to key libraries (PyTorch 2.7.1, Keras 3.10.0, Pandas 2.3.0, SciPy 1.16.0, Geopandas 1.1.0, TensorFlow Metadata 1.17.1, Ruff 0.12.0; h5py 3.13.0 and py-pycocotools 2.0.9 to resolve numpy conflicts) and aligned dependencies to maintain compatibility with newer NumPy releases. Upgraded static type checking and Python tooling (Mypy 1.16.0; Python 3.9 requirement; pathspec 0.9+). Improved build/test workflow with Bazel patches and added local repo testing guidance. Minor but meaningful documentation improvements in packaging tutorials and attribution. Result: enhanced stability, compatibility, and performance for ML workloads, smoother installation for users, and reduced maintenance burden across three repositories.
June 2025 performance highlights: Delivered a comprehensive ML/data-science stack upgrade across the spack-packages and core Spack repositories, stabilized build/test workflows, and enhanced developer tooling. Implemented forward-compatible updates to key libraries (PyTorch 2.7.1, Keras 3.10.0, Pandas 2.3.0, SciPy 1.16.0, Geopandas 1.1.0, TensorFlow Metadata 1.17.1, Ruff 0.12.0; h5py 3.13.0 and py-pycocotools 2.0.9 to resolve numpy conflicts) and aligned dependencies to maintain compatibility with newer NumPy releases. Upgraded static type checking and Python tooling (Mypy 1.16.0; Python 3.9 requirement; pathspec 0.9+). Improved build/test workflow with Bazel patches and added local repo testing guidance. Minor but meaningful documentation improvements in packaging tutorials and attribution. Result: enhanced stability, compatibility, and performance for ML workloads, smoother installation for users, and reduced maintenance burden across three repositories.
May 2025 performance summary focusing on core stack upgrades, geospatial tooling, packaging improvements, CI stability, and a Lightning-AI bug fix. Delivered across spack/spack, spack/spack-packages, and Lightning-AI/pytorch-lightning. Key outcomes include coordinated updates to the core Python scientific stack (NumPy, SciPy, Matplotlib, Shapely, h5py, TorchMetrics, JAX) and ML tooling, refreshed geospatial tooling with GDAL 3.11.0 and datacube 1.9.3, and packaging/distro improvements (py-jsonargparse 4.39.0, Kornia 0.8.1) plus Python 3.12 compatibility considerations and CI stability enhancements. A CLI deprecation fix in PyTorch Lightning preserves functionality across older environments. Business value: improved reliability, security posture, faster access to latest features, and reduced maintenance overhead for downstream users.
May 2025 performance summary focusing on core stack upgrades, geospatial tooling, packaging improvements, CI stability, and a Lightning-AI bug fix. Delivered across spack/spack, spack/spack-packages, and Lightning-AI/pytorch-lightning. Key outcomes include coordinated updates to the core Python scientific stack (NumPy, SciPy, Matplotlib, Shapely, h5py, TorchMetrics, JAX) and ML tooling, refreshed geospatial tooling with GDAL 3.11.0 and datacube 1.9.3, and packaging/distro improvements (py-jsonargparse 4.39.0, Kornia 0.8.1) plus Python 3.12 compatibility considerations and CI stability enhancements. A CLI deprecation fix in PyTorch Lightning preserves functionality across older environments. Business value: improved reliability, security posture, faster access to latest features, and reduced maintenance overhead for downstream users.
April 2025 monthly wrap-up for Spack and related package repositories. Delivered major feature enrichments, broad dependency updates, and stability improvements across spack/spack, spack/spack-packages, and numpy/numpy. Business value-focused outcomes include expanded packaging coverage for contemporary data-science stacks, reduced build failures on macOS/Fortran toolchains, and improved developer experience through added type hints and clearer environment setup. Key accomplishments include: - New Python packages added: py-wids and py-litdata, integrated across core repos. - Widespread package version upgrades for critical dependencies (e.g., PyTorch v2.7.0, NumPy v2.2.5, Pillow v11.2.1, shapely v2.1.0, webdataset v0.2.111, torchgeo v0.7.0, nbstripout v0.8.1, torchmetrics v1.7.1, grpcio v1.71.0, libpng v1.6.47, pykwalify v1.8.0). - Infrastructure and build hardening: added missing compiler dependencies; removed runtime errors for Fortran compilers; fixed macOS ld linker support for NumPy. - Platform and tooling improvements: PyTorch build fix for Apple Clang 17; NumPy macOS linker cleanup; Thrift recipe overhaul; type hints added to setup_*environment functions. Overall impact: stronger, more current packaging coverage with improved build reliability across macOS and multi-platform environments, enabling faster provisioning of reproducible data-science work environments.
April 2025 monthly wrap-up for Spack and related package repositories. Delivered major feature enrichments, broad dependency updates, and stability improvements across spack/spack, spack/spack-packages, and numpy/numpy. Business value-focused outcomes include expanded packaging coverage for contemporary data-science stacks, reduced build failures on macOS/Fortran toolchains, and improved developer experience through added type hints and clearer environment setup. Key accomplishments include: - New Python packages added: py-wids and py-litdata, integrated across core repos. - Widespread package version upgrades for critical dependencies (e.g., PyTorch v2.7.0, NumPy v2.2.5, Pillow v11.2.1, shapely v2.1.0, webdataset v0.2.111, torchgeo v0.7.0, nbstripout v0.8.1, torchmetrics v1.7.1, grpcio v1.71.0, libpng v1.6.47, pykwalify v1.8.0). - Infrastructure and build hardening: added missing compiler dependencies; removed runtime errors for Fortran compilers; fixed macOS ld linker support for NumPy. - Platform and tooling improvements: PyTorch build fix for Apple Clang 17; NumPy macOS linker cleanup; Thrift recipe overhaul; type hints added to setup_*environment functions. Overall impact: stronger, more current packaging coverage with improved build reliability across macOS and multi-platform environments, enabling faster provisioning of reproducible data-science work environments.
March 2025 highlights a comprehensive set of Spack and related packaging updates delivering better installability, broader Python/version coverage, and improved build reliability for ML/vision toolchains. The work spanned spack/spack, spack/spack-packages, and Lightning-AI/torchmetrics, focusing on new version support, compatibility constraints, and CUDA/build fixes, with coordinated packaging cleanups for easier maintenance and future upgrades.
March 2025 highlights a comprehensive set of Spack and related packaging updates delivering better installability, broader Python/version coverage, and improved build reliability for ML/vision toolchains. The work spanned spack/spack, spack/spack-packages, and Lightning-AI/torchmetrics, focusing on new version support, compatibility constraints, and CUDA/build fixes, with coordinated packaging cleanups for easier maintenance and future upgrades.
February 2025 performance and packaging summary: Delivered substantial PyTorch ecosystem upgrades and Python packaging enhancements across spack/spack and spack-packages, with a focus on production-ready performance, broader runtime support, and deployment reliability. Key outcomes include PyTorch 2.6.0 integration with Flash Attention enabled by default for CUDA/ROCm builds, refined TorchGeo integration and dependency alignment, expanded Python runtime support (3.8–3.13) with updated core libraries, and a stabilized geospatial stack (GDAL 3.10.2). In Torchmetrics, IOU type hints were tightened for safer detection module inputs. Overall impact: faster ML workloads, easier upgrades, and a more robust Python data stack for downstream teams.
February 2025 performance and packaging summary: Delivered substantial PyTorch ecosystem upgrades and Python packaging enhancements across spack/spack and spack-packages, with a focus on production-ready performance, broader runtime support, and deployment reliability. Key outcomes include PyTorch 2.6.0 integration with Flash Attention enabled by default for CUDA/ROCm builds, refined TorchGeo integration and dependency alignment, expanded Python runtime support (3.8–3.13) with updated core libraries, and a stabilized geospatial stack (GDAL 3.10.2). In Torchmetrics, IOU type hints were tightened for safer detection module inputs. Overall impact: faster ML workloads, easier upgrades, and a more robust Python data stack for downstream teams.
January 2025 performance summary for the Spack ecosystems (spack/spack and spack-packages). Delivered a broad set of version upgrades across core libraries and ML toolchains, implemented critical bug fixes, and strengthened packaging practices to improve stability, reproducibility, and time-to-deploy for downstream users. Highlights include major version bumps for SciPy, Pillow, NumPy, scikit-learn/scikit-image, PyTorch-related tooling, and new/updated packages; complemented by targeted fixes (trailing slashes, PyTorch variant handling) and metadata improvements for Python compatibility.
January 2025 performance summary for the Spack ecosystems (spack/spack and spack-packages). Delivered a broad set of version upgrades across core libraries and ML toolchains, implemented critical bug fixes, and strengthened packaging practices to improve stability, reproducibility, and time-to-deploy for downstream users. Highlights include major version bumps for SciPy, Pillow, NumPy, scikit-learn/scikit-image, PyTorch-related tooling, and new/updated packages; complemented by targeted fixes (trailing slashes, PyTorch variant handling) and metadata improvements for Python compatibility.
December 2024 performance summary focused on delivering up-to-date data-science tooling via Spack packaging improvements, policy updates, and robustness enhancements across three repositories (spack/spack-packages, spack/spack, ROCm/jax). The work moves users toward newer Python runtimes, reduces build failures, and strengthens CI reliability through cross-repo coordination and explicit versioning.
December 2024 performance summary focused on delivering up-to-date data-science tooling via Spack packaging improvements, policy updates, and robustness enhancements across three repositories (spack/spack-packages, spack/spack, ROCm/jax). The work moves users toward newer Python runtimes, reduces build failures, and strengthens CI reliability through cross-repo coordination and explicit versioning.
November 2024 highlights a broad Spack ecosystem upgrade across spack/spack and spack/spack-packages, delivering extensive core-library bumps, Python-version readiness, and packaging/compatibility improvements to enable downstream adoption of newer Python and library features. The work improves stability, security posture, and developer productivity by standardizing updates across multiple repositories and aligning with modern language versions.
November 2024 highlights a broad Spack ecosystem upgrade across spack/spack and spack/spack-packages, delivering extensive core-library bumps, Python-version readiness, and packaging/compatibility improvements to enable downstream adoption of newer Python and library features. The work improves stability, security posture, and developer productivity by standardizing updates across multiple repositories and aligning with modern language versions.
Monthly Summary for 2024-10 focused on delivering stable packaging updates and improving ecosystem coherence in Spack. Key work centered on enabling PyTorch 2.5.1 and Py-IPyMPL 0.9.4 support, tightening dependencies for build/runtime compatibility, and cleaning up documentation to reflect current scope. These changes enhance reproducibility and data science workflow reliability across user environments.
Monthly Summary for 2024-10 focused on delivering stable packaging updates and improving ecosystem coherence in Spack. Key work centered on enabling PyTorch 2.5.1 and Py-IPyMPL 0.9.4 support, tightening dependencies for build/runtime compatibility, and cleaning up documentation to reflect current scope. These changes enhance reproducibility and data science workflow reliability across user environments.
Overview of all repositories you've contributed to across your timeline