blosc: add build-blosc.yml for riscv64 wheels (#1500)

* **Package**: `blosc`
* **Version**: `1.11.4`
* **Source**: https://github.com/blosc/python-blosc
* **Docs**: https://github.com/blosc/python-blosc

Compiles the vendored c-blosc C library (with LZ4 and zlib codecs) into a Python extension via CMake/scikit-build. Upstream publishes no riscv64 wheel.

Mirrors [upstream's `cibuildwheels.yml`](https://github.com/blosc/python-blosc/blob/v1.11.4/.github/workflows/cibuildwheels.yml).

**Differs from upstream**
- Nothing beyond the riscv64 image.

**Testing**
- same as upstream, `python -m blosc.test`

**License**: Wheel bundles c-blosc's own BSD licence plus its statically-linked LZ4 (BSD) and zlib (zlib licence); the vendored zstd (BSD) copy ships no licence file at all, so the patch restores one.

**Patches**
- `0001-Ship-the-licences-of-what-the-wheel-actually-bundles.patch` - To upstream (not submitted, no cross-repo issue/PR). Adds a `license_files` list to setup.py; without it only the wrapper's own LICENSE.txt ships. Reproduces off riscv64 too (verified locally on macOS arm64, an equally SIMD-unsupported architecture for this c-blosc version).

Built and tested locally (macOS arm64, no SIMD path, same fallback riscv64 will take): 38 passed, 1 skipped (psutil-gated leak test, same as upstream's own CI).

Author: luhenry

.github/workflows/build-blosc.yml

@@ -0,0 +1,116 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# This workflow is based on the `build_wheels` job of
+# https://github.com/blosc/python-blosc/blob/v1.11.4/.github/workflows/cibuildwheels.yml
+name: Build blosc wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'blosc version to build (git tag without leading v, e.g. 1.11.4)'
+        required: true
+        default: '1.11.4'
+  pull_request:
+    paths:
+      - '.github/workflows/build-blosc.yml'
+      - 'patches/blosc/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ inputs.version || '1.11.4' }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read  # to fetch code (actions/checkout)
+
+env:
+  # `inputs.version` is empty on pull_request events; default to 1.11.4 there.
+  BLOSC_VERSION: ${{ inputs.version || '1.11.4' }}
+  MANYLINUX_RISCV64_IMAGE: quay.io/pypa/manylinux_2_39_riscv64
+
+jobs:
+  setup:
+    uses: $/.github/workflows/_setup.yml
+
+  build_wheels:
+    needs: [setup]
+    name: Build blosc ${{ inputs.version || '1.11.4' }} ${{ matrix.python }}-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 45
+    strategy:
+      fail-fast: false
+      matrix:
+        python: [cp312, cp313, cp314, cp314t]
+
+    steps:
+      - name: Checkout python-blosc v${{ env.BLOSC_VERSION }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: blosc/python-blosc
+          ref: v${{ env.BLOSC_VERSION }}
+          submodules: recursive
+          persist-credentials: false
+
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          path: python-wheels
+          persist-credentials: false
+
+      - name: Patch python-blosc source
+        run: git apply python-wheels/patches/blosc/${{ env.BLOSC_VERSION }}/*.patch
+
+      - uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
+        with:
+          output-dir: wheelhouse/
+          only: ${{ matrix.python }}-manylinux_riscv64
+        env:
+          CIBW_MANYLINUX_RISCV64_IMAGE: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+          # C-Blosc's own CMakeLists.txt gates SSE2/AVX2 on a recognized x86
+          # CMAKE_SYSTEM_PROCESSOR and warns-not-fails otherwise, so riscv64
+          # falls straight back to its portable shuffle-generic.c path -- no
+          # patch needed for the SIMD codec gating itself.
+          CIBW_ENVIRONMENT: >-
+            PIP_EXTRA_INDEX_URL=https://pypi.riseproject.dev/simple/
+            PIP_ONLY_BINARY=numpy
+          CIBW_TEST_REQUIRES: numpy
+          CIBW_TEST_COMMAND: python -m blosc.test
+
+      - name: Check wheel contents
+        run: |
+          python3 - wheelhouse/*.whl <<'EOF'
+          import sys, zipfile
+
+          names = zipfile.ZipFile(sys.argv[1]).namelist()
+          exts = {n for n in names if n.startswith("blosc/") and n.endswith(".so")}
+          assert len(exts) == 1 and next(iter(exts)).startswith("blosc/blosc_extension"), exts
+
+          licences = {n.split(".dist-info/licenses/", 1)[1] for n in names
+                      if ".dist-info/licenses/" in n and not n.endswith("/")}
+          assert licences == {
+              "LICENSE.txt",
+              "blosc/c-blosc/LICENSE.txt",
+              "blosc/c-blosc/LICENSES/BITSHUFFLE.txt",
+              "blosc/c-blosc/LICENSES/FASTLZ.txt",
+              "blosc/c-blosc/LICENSES/LZ4.txt",
+              "blosc/c-blosc/LICENSES/ZLIB.txt",
+              "blosc/c-blosc/LICENSES/ZSTD.txt",
+          }, licences
+          EOF
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: blosc-${{ env.BLOSC_VERSION }}-${{ matrix.python }}-manylinux_riscv64
+          path: wheelhouse/*.whl
+          if-no-files-found: error
+
+  publish:
+    name: Publish blosc ${{ inputs.version || '1.11.4' }}
+    needs: [setup, build_wheels]
+    permissions:
+      contents: write
+      pull-requests: write
+    uses: $/.github/workflows/_publish-wheel.yml
+    with:
+      artifact-pattern: blosc-${{ inputs.version || '1.11.4' }}-*-manylinux_riscv64

patches/blosc/1.11.4/0001-Ship-the-licences-of-what-the-wheel-actually-bundles.patch

@@ -0,0 +1,92 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Tue, 8 Sep 2026 00:00:00 +0000
+Subject: [PATCH] Ship the licences of what the wheel actually bundles
+
+setup.py sets no `license_files`, so setuptools falls back to its
+default `LICEN[CS]E*` glob at the project root, which only ever picks
+up this project's own LICENSE.txt (confirmed by building the wheel
+locally: `blosc-1.11.4.dist-info/licenses/` held just that one file).
+
+That leaves out the licences of the c-blosc submodule this build
+statically compiles into the extension: c-blosc's own LICENSE.txt
+(blosc.c, blosclz.c, shuffle.c, ...), and the codecs its CMakeLists.txt
+includes by default (LZ4, zlib, and the FastLZ- and Bitshuffle-derived
+code in blosclz.c/bitshuffle-generic.c, all credited in
+c-blosc/LICENSES/). Snappy stays out (deactivated by default, matching
+this build) and so does the Windows-only STDINT.txt shim.
+
+c-blosc/internal-complibs/zstd-1.5.6 is missing a licence file
+entirely -- confirmed byte-identical to upstream zstd v1.5.6's lib/
+tree, whose LICENSE (BSD, at the zstd repo root) never got carried
+over when it was vendored. Restoring that exact file lets
+license_files pick it up the same way as the other codecs' notices,
+rather than leaving zstd unlicensed in the wheel.
+
+Upstream-Status: To upstream [not submitted: no cross-repo issue/PR contributions from this port]
+
+Signed-off-by: Ludovic Henry <git@ludovic.dev>
+---
+ blosc/c-blosc/LICENSES/ZSTD.txt | 30 ++++++++++++++++++++++++++++++
+ setup.py                        |  9 +++++++++
+ 2 files changed, 39 insertions(+)
+ create mode 100644 blosc/c-blosc/LICENSES/ZSTD.txt
+
+diff --git a/blosc/c-blosc/LICENSES/ZSTD.txt b/blosc/c-blosc/LICENSES/ZSTD.txt
+new file mode 100644
+index 0000000..7580028
+--- /dev/null
++++ b/blosc/c-blosc/LICENSES/ZSTD.txt
+@@ -0,0 +1,30 @@
++BSD License
++
++For Zstandard software
++
++Copyright (c) Meta Platforms, Inc. and affiliates. All rights reserved.
++
++Redistribution and use in source and binary forms, with or without modification,
++are permitted provided that the following conditions are met:
++
++ * Redistributions of source code must retain the above copyright notice, this
++   list of conditions and the following disclaimer.
++
++ * Redistributions in binary form must reproduce the above copyright notice,
++   this list of conditions and the following disclaimer in the documentation
++   and/or other materials provided with the distribution.
++
++ * Neither the name Facebook, nor Meta, nor the names of its contributors may
++   be used to endorse or promote products derived from this software without
++   specific prior written permission.
++
++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
++ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
++WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
++DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
++ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
++(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
++LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
++ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
++SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+diff --git a/setup.py b/setup.py
+index 8f1748d..2841ef3 100644
+--- a/setup.py
++++ b/setup.py
+@@ -98,6 +98,15 @@ if __name__ == '__main__':
+         setup_requires=['scikit-build'],
+         tests_require=['numpy', 'psutil'],
+         packages = ['blosc'],
++        license_files = [
++            'LICENSE.txt',
++            'blosc/c-blosc/LICENSE.txt',
++            'blosc/c-blosc/LICENSES/BITSHUFFLE.txt',
++            'blosc/c-blosc/LICENSES/FASTLZ.txt',
++            'blosc/c-blosc/LICENSES/LZ4.txt',
++            'blosc/c-blosc/LICENSES/ZLIB.txt',
++            'blosc/c-blosc/LICENSES/ZSTD.txt',
++        ],
+         )
+ elif __name__ == '__mp_main__':
+     # This occurs from `cpuinfo 4.0.0` using multiprocessing to interrogate the
+--
+2.43.0