From 9ae8b56fec07e62c8e71b52915fb89f3b3fdd5e1 Mon Sep 17 00:00:00 2001
From: Casper da Costa-Luis <casper.dcl@physics.org>
Date: Thu, 7 May 2026 15:00:27 +0100
Subject: [PATCH 1/6] CI: bump workflow actions

---
 .github/workflows/build.yml | 44 ++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 35c44d989..bd5a476f4 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -30,7 +30,7 @@ jobs:
         python-version: [3.11]
         numpy-version: [1.25]
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with: {fetch-depth: 0, submodules: recursive}
     - id: reqs
       name: set requirements
@@ -38,7 +38,7 @@ jobs:
         envname="${GITHUB_REPOSITORY##*/}-${GITHUB_RUN_ID}.${GITHUB_RUN_NUMBER}"
         echo "envname=$envname" >> $GITHUB_OUTPUT
         sed -ri -e 's/^(name: ).*/\1$envname/' -e '/ python /d' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' scripts/cil_development.yml
-    - uses: conda-incubator/setup-miniconda@v3
+    - uses: conda-incubator/setup-miniconda@v4
       with:
         python-version: ${{ matrix.python-version }}
         environment-file: scripts/cil_development.yml
@@ -69,11 +69,11 @@ jobs:
         - {python-version: '3.10', numpy-version: 1.23}
         - {python-version: 3.12, numpy-version: 1.26}
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with: {fetch-depth: 0, submodules: recursive}
     - name: set requirements
       run: sed -ri -e '/ python /d' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' -e 's/cuda*//' -e '/tigre/d' scripts/cil_development.yml
-    - uses: conda-incubator/setup-miniconda@v3
+    - uses: conda-incubator/setup-miniconda@v4
       with:
         python-version: ${{ matrix.python-version }}
         environment-file: scripts/cil_development.yml
@@ -125,7 +125,7 @@ jobs:
         os: ${{ fromJson(needs.conda-matrix.outputs.os) }}
         include: ${{ fromJson(needs.conda-matrix.outputs.include) }}
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
         submodules: recursive
@@ -158,15 +158,15 @@ jobs:
         os: ${{ fromJson(needs.conda-matrix.outputs.os) }}
         include: ${{ fromJson(needs.conda-matrix.outputs.include-numpy) }}
     steps:
-    - uses: actions/checkout@v4
-    - uses: conda-incubator/setup-miniconda@v3
+    - uses: actions/checkout@v6
+    - uses: conda-incubator/setup-miniconda@v4
       with:
         python-version: ${{ matrix.python-version }}
         mamba-version: "*"
         channels: conda-forge
         conda-remove-defaults: "true"
     - run: conda install conda-build
-    - uses: actions/download-artifact@v4
+    - uses: actions/download-artifact@v8
       with:
         name: cil-py${{ matrix.python-version }}-${{ matrix.os }}
         path: dist
@@ -180,13 +180,13 @@ jobs:
     runs-on: ubuntu-latest
     needs: conda-test
     steps:
-    - uses: actions/checkout@v4
-    - uses: conda-incubator/setup-miniconda@v3
+    - uses: actions/checkout@v6
+    - uses: conda-incubator/setup-miniconda@v4
       with:
         mamba-version: "*"
         channels: conda-forge
         conda-remove-defaults: "true"
-    - uses: actions/download-artifact@v4
+    - uses: actions/download-artifact@v8
       with: {pattern: cil-py*-*, path: dist, merge-multiple: true}
     - run: mamba install anaconda-client
     - name: anaconda upload -c ccpi
@@ -205,12 +205,12 @@ jobs:
     defaults: {run: {shell: 'bash -el {0}', working-directory: docs}}
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
         submodules: recursive
         ref: ${{ github.event.pull_request.head.sha || github.ref }} # fix SHA
-    - uses: conda-incubator/setup-miniconda@v3
+    - uses: conda-incubator/setup-miniconda@v4
       with:
         python-version: 3.12
         mamba-version: "*"
@@ -230,12 +230,12 @@ jobs:
         conda list
     - run: pip install ..
     - name: checkout docs
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         path: docs/build
         ref: gh-pages
     - id: pages
-      uses: actions/configure-pages@v5
+      uses: actions/configure-pages@v6
     - name: update web pages (jekyll)
       run: make JEKYLLOPTS="--baseurl ${{ steps.pages.outputs.base_path }}" web-deps web
       env: {JEKYLL_ENV: production}
@@ -245,7 +245,7 @@ jobs:
         docs_dir="${docs_dir//\//_}"
         if test "$docs_dir" = master; then docs_dir=nightly; fi
         make BUILDSUBDIR="$docs_dir" dirhtml
-    - uses: actions/upload-artifact@v4
+    - uses: actions/upload-artifact@v7
       with:
         name: DocumentationHTML
         path: docs/build
@@ -263,7 +263,7 @@ jobs:
       contents: read
       packages: write
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
         submodules: recursive
@@ -272,8 +272,8 @@ jobs:
       with:
         docker-images: false
         large-packages: false
-    - uses: docker/setup-buildx-action@v3
-    - uses: docker/metadata-action@v5
+    - uses: docker/setup-buildx-action@v4
+    - uses: docker/metadata-action@v6
       id: meta
       with:
         images: ghcr.io/${{ github.repository }}
@@ -283,13 +283,13 @@ jobs:
           type=semver,pattern={{major}}.{{minor}}
         labels: |
           org.opencontainers.image.licenses=Apache-2.0 AND BSD-3-Clause AND GPL-3.0
-    - uses: docker/login-action@v3
+    - uses: docker/login-action@v4
       if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags')
       with:
         registry: ghcr.io
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
-    - uses: docker/build-push-action@v6
+    - uses: docker/build-push-action@v7
       with:
         cache-from: type=gha
         cache-to: type=gha,mode=max
@@ -300,7 +300,7 @@ jobs:
       run: >
         docker run --rm -v .:/CIL tomographicimaging/cil:test /bin/bash -c
         'python -m unittest discover -v /CIL/Wrappers/Python/test'
-    - uses: docker/build-push-action@v6
+    - uses: docker/build-push-action@v7
       with:
         cache-from: type=gha
         cache-to: type=gha,mode=max

From f9f992df7a2380ce95bdbaf5f4d24c1ea92901c7 Mon Sep 17 00:00:00 2001
From: Casper da Costa-Luis <casper.dcl@physics.org>
Date: Thu, 7 May 2026 14:58:14 +0100
Subject: [PATCH 2/6] migrate to rattler-build

- follow-up to #2320
---
 .github/workflows/README.md |   8 +--
 .github/workflows/build.yml |  51 +++++-----------
 .gitignore                  |   1 +
 CHANGELOG.md                |   2 +
 recipe.yaml                 | 113 ++++++++++++++++++++++++++++++++++++
 recipe/bld.bat              |   8 ---
 recipe/build.sh             |  16 -----
 recipe/meta.yaml            |  78 -------------------------
 8 files changed, 136 insertions(+), 141 deletions(-)
 create mode 100644 recipe.yaml
 delete mode 100644 recipe/bld.bat
 delete mode 100755 recipe/build.sh
 delete mode 100644 recipe/meta.yaml

diff --git a/.github/workflows/README.md b/.github/workflows/README.md
index 8e8080dc3..2f4bf3cc3 100644
--- a/.github/workflows/README.md
+++ b/.github/workflows/README.md
@@ -12,7 +12,7 @@ The jobs are:
   + uses default (GitHub-hosted) runners to run tests on the min & max supported Python & NumPy versions
   + `python -m unittest discover -v ./Wrappers/Python/test`
 - `conda`
-  + uses `conda-build` to build the conda package (saved as a build artifact named `cil-py3.m-OS`)
+  + uses `rattler-build` to build the conda package (saved as a build artifact named `conda-py3.m-OS`)
 - `docs`
   + uses `docs/docs_environment.yml` plus `make -C docs` to build the documentation (saved as a build artifact named `DocumentationHTML`)
   + renders to the `gh-pages` branch on `master` (nightly) pushes or on tag (release) pushes
@@ -39,12 +39,12 @@ When opening or modifying a pull request to `master`, two variants are built and
 > [!NOTE]
 > The action publishes `ccpi` as well as `https://tomography.stfc.ac.uk/conda/` conda channels. We will eventually move to conda-forge instead.
 
-It looks for conda-build dependencies in the channels listed [here](./build.yml#L118). If you add any new dependencies, the appropriate channels need to be added to this line.
+It looks for dependencies in the channels listed in the `rattler-build-action`'s `build-args` [here](./build.yml). If you add any new dependencies, the appropriate channels need to be added to this line.
 
 > [!TIP]
-> The `conda` job builds the `*.tar.bz2` package and uploads it as an artifact called `cil-py3.m-OS`.
+> The `conda` job builds the `*.conda` package and uploads it as an artifact called `conda-py3.m-OS`.
 > It can be found by going to the "Actions" tab, and selecting the appropriate run of `.github/workflows/build.yml`, or by clicking on the tick on the action in the "All checks have passed/failed" section of a PR. When viewing the "Summary" for the run of the action, there is an "Artifact" section at the bottom of the page.
-> Clicking on `cil-py3.m-OS` allows you to download a zip folder containing the `*.tar.bz2` file.
+> Clicking on `conda-py3.m-OS` allows you to download a zip folder containing the `*.conda` file.
 
 ### docs
 
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index bd5a476f4..7f53bd489 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -87,7 +87,6 @@ jobs:
       python-version: ${{ steps.matrix.outputs.python-version }}
       numpy-version: ${{ steps.matrix.outputs.numpy-version }}
       os: ${{ steps.matrix.outputs.os }}
-      include: ${{ steps.matrix.outputs.include }}
       include-numpy: ${{ steps.matrix.outputs.include-numpy }}
     steps:
     - id: matrix
@@ -109,21 +108,16 @@ jobs:
           fi
         fi
         if $include_max; then
-          echo "include=[{'python-version': 3.12, 'os': 'ubuntu'}, {'python-version': 3.12, 'os': 'windows'}]" >> $GITHUB_OUTPUT
           echo "include-numpy=[{'python-version': 3.12, 'numpy-version': 1.26, 'os': 'ubuntu'}, {'python-version': 3.12, 'numpy-version': 1.26, 'os': 'windows'}]" >> $GITHUB_OUTPUT
         else
-          echo "include=[]" >> $GITHUB_OUTPUT
           echo "include-numpy=[]" >> $GITHUB_OUTPUT
         fi
   conda-build:
-    defaults: {run: {shell: 'bash -el {0}'}}
     runs-on: ${{ matrix.os }}-${{ matrix.os == 'ubuntu' && '24.04' || '2022' }}
     needs: conda-matrix
     strategy:
       matrix:
-        python-version: ${{ fromJson(needs.conda-matrix.outputs.python-version) }}
         os: ${{ fromJson(needs.conda-matrix.outputs.os) }}
-        include: ${{ fromJson(needs.conda-matrix.outputs.include) }}
     steps:
     - uses: actions/checkout@v6
       with:
@@ -132,21 +126,11 @@ jobs:
         ref: ${{ github.event.pull_request.head.sha || github.ref }} # fix SHA
     - if: matrix.os == 'windows'
       uses: ilammy/msvc-dev-cmd@v1
-    - uses: conda-incubator/setup-miniconda@v3
-      with:
-        python-version: ${{ matrix.python-version }}
-        mamba-version: "*"
-        channels: conda-forge
-        conda-remove-defaults: "true"
-    - run: conda install conda-build
-    - name: conda build
-      run: >
-        conda build -c conda-forge -c https://software.repos.intel.com/python/conda -c ccpi --override-channels --python=${{ matrix.python-version }}
-        --no-test --output-folder dist recipe
-    - uses: actions/upload-artifact@v4
+    - uses: prefix-dev/rattler-build-action@v0.2.37
       with:
-        name: cil-py${{ matrix.python-version }}-${{ matrix.os }}
-        path: dist/*/cil-*
+        recipe-path: recipe.yaml
+        build-args: --experimental -c conda-forge -c https://software.repos.intel.com/python/conda -c ccpi --no-test
+        artifact-name: conda-${{ matrix.os }}
   conda-test:
     defaults: {run: {shell: 'bash -el {0}'}}
     runs-on: ${{ matrix.os }}-${{ matrix.os == 'ubuntu' && '24.04' || '2022' }}
@@ -168,37 +152,34 @@ jobs:
     - run: conda install conda-build
     - uses: actions/download-artifact@v8
       with:
-        name: cil-py${{ matrix.python-version }}-${{ matrix.os }}
-        path: dist
+        name: conda-${{ matrix.os }}
+        path: output
     - name: conda test
       run: >
         conda build -c conda-forge  -c https://software.repos.intel.com/python/conda -c ccpi --override-channels --python=${{ matrix.python-version }}
-        --test dist/*/cil-* --extra-deps numpy=${{ matrix.numpy-version }}
+        --test output/*/cil-* --extra-deps numpy=${{ matrix.numpy-version }}
   conda-upload:
     if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags')
-    defaults: {run: {shell: 'bash -el {0}', working-directory: dist}}
+    defaults: {run: {shell: 'bash -el {0}', working-directory: output}}
     runs-on: ubuntu-latest
     needs: conda-test
     steps:
     - uses: actions/checkout@v6
-    - uses: conda-incubator/setup-miniconda@v4
-      with:
-        mamba-version: "*"
-        channels: conda-forge
-        conda-remove-defaults: "true"
+    - uses: prefix-dev/rattler-build-action@v0.2.37
+      with: {setup-only: true}
     - uses: actions/download-artifact@v8
-      with: {pattern: cil-py*-*, path: dist, merge-multiple: true}
-    - run: mamba install anaconda-client
-    - name: anaconda upload -c ccpi
+      with: {pattern: conda-*, path: output, merge-multiple: true}
+    - name: conda upload -c ccpi
       run: >
-        anaconda -v -t ${{ secrets.CCPI_CONDA_TOKEN }} upload --force
-        --label ${{ startsWith(github.ref, 'refs/tags') && 'main' || 'dev' }} */cil-*
+        rattler-build upload anaconda */*.conda -f
+        -o ccpi -a ${{ secrets.CCPI_CONDA_TOKEN }}
+        -c ${{ startsWith(github.ref, 'refs/tags') && 'main' || 'dev' }}
     - if: startsWith(github.ref, 'refs/tags')
       name: conda upload -c tomography.stfc.ac.uk/conda
       run: |
         echo '${{ secrets.STFC_SSH_KEY }}' > ./key
         chmod 600 ./key
-        rsync -e 'ssh -o StrictHostKeyChecking=no -i ./key' -R */cil-* '${{ secrets.STFC_SSH_HOST }}:${{ secrets.STFC_SSH_CONDA_DIR }}'
+        rsync -e 'ssh -o StrictHostKeyChecking=no -i ./key' -R */*.conda '${{ secrets.STFC_SSH_HOST }}:${{ secrets.STFC_SSH_CONDA_DIR }}'
         ssh -o StrictHostKeyChecking=no -i ./key ${{ secrets.STFC_SSH_HOST }} \
           'bash -lic "conda index --bz2 --zst --run-exports --channeldata --rss -n ccpi ${{ secrets.STFC_SSH_CONDA_DIR }}"'
   docs:
diff --git a/.gitignore b/.gitignore
index 755ad9fd9..6823c1cf5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 /build*
+/output/
 __pycache__/
 /Wrappers/Python/cil-*.dist-info/
 /Wrappers/Python/cil/include/
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc213eccd..ace85d0e6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,8 @@
     - Add prefix argument to TIFFStackReader to load a subset of TIFF files in
     a folder (#2239)
     - Update ASTRA interface to `direct_FP3D/BP3D` removing copies for GPU `ProjectionOperator` calls (#2134)
+  - Testing:
+    - migrate from `conda build` to `rattler-build`
 
 * 25.0.0
   - New features:
diff --git a/recipe.yaml b/recipe.yaml
new file mode 100644
index 000000000..be805de36
--- /dev/null
+++ b/recipe.yaml
@@ -0,0 +1,113 @@
+schema_version: 1
+
+context:
+  name: ${{ load_from_file("pyproject.toml").project.name }} # ratter-build --experimental
+  python_min: ${{ load_from_file("pyproject.toml")['project']['requires-python'] | replace(">=", "") }} # ratter-build --experimental
+  build_number: 0
+  version: ${{ git.latest_tag(".") | replace("v", "") }} # .dev${{ build_number }}+g${{ git.head_rev(".") }} # ratter-build --experimental
+  test_gpu: ${{ env.get("TESTS_FORCE_GPU", default="") | bool }}
+  # used multiple times, so defined once here to avoid repetition
+  ipp_version: '2021.12.*'
+  astra_version: '2.1.*'
+
+package:
+  name: ${{ name }}
+  version: ${{ version }}
+
+source:
+  path: .
+
+build:
+  number: ${{ build_number }}
+  noarch: python
+  script:
+    content:
+      - if: win
+        then: pip install . -vv --prefix=%PREFIX%
+      - if: osx
+        then: pip install . -vv --prefix=$PREFIX -Ccmake.args="-DOPENMP_LIBRARIES=${CONDA_PREFIX}/lib -DOPENMP_INCLUDES=${CONDA_PREFIX}/include"
+      - if: linux
+        then: pip install . -vv --prefix=$PREFIX
+    env:
+      CMAKE_BUILD_TYPE: Release
+      CMAKE_GENERATOR: Ninja
+
+requirements:
+  build:
+    - cmake >=3.16
+    - ninja
+    - ${{ compiler('cxx') }}
+  host:
+    - if: linux
+      then: libgomp
+    - if: osx
+      then: llvm-openmp
+    - if: x86_64
+      then:
+      - ipp-include ${{ ipp_version }}
+      - ipp-devel ${{ ipp_version }}
+    - python ${{ python_min ~ '.*' }}
+    - pip
+    - setuptools >=64
+    - setuptools_scm >=8
+    - scikit-build-core >=0.10
+  run:
+    - python >=${{ python_min }}
+    - if: x86_64
+      then: ipp ${{ ipp_version }}
+    - numpy >=1.23,<2
+    - scipy >=1.4
+    - h5py
+    - pillow
+    - pywavelets
+    - cil-data >=22
+    - tqdm
+    - numba
+  # version constraints of optional dependencies
+  run_constraints:
+    - tomophantom >=3.0.3
+    - astra-toolbox >=1.9.9.dev5
+    - tigre >=2.4
+    - ccpi-regulariser >=24.0.1
+    - olefile >=0.46
+    - zenodo_get >=1.6
+
+tests:
+  - python:
+      imports:
+        - cil
+        - cil.framework
+        - cil.version
+      pip_check: false
+      python_version: ["${{ python_min ~ '.*' }}", "3.*"]
+  - script:
+      - pip install unittest-parametrize
+      - python -m unittest discover -v -s Wrappers/Python/test
+    files:
+      source:
+        - ./Wrappers/Python/test
+    requirements:
+      run:
+        - pip
+        - python-wget
+        - if: linux
+          then: cvxpy !=1.8.2
+        - scikit-image
+        - packaging
+        - tomophantom 3.0.3.*
+        - if: not osx
+          then: ccpi-regulariser 24.0.1.*
+        - if: test_gpu
+          then:
+          - tigre 2.6.*
+          - astra-toolbox ${{ astra_version }} cuda*
+          else: astra-toolbox ${{ astra_version }} py*
+        - matplotlib-base >=3.3
+        - zenodo_get >=1.6
+        - dxchange >=0.2.1
+        - olefile >=0.46
+
+about:
+  license: Apache-2.0
+  summary: CCPi Core Imaging Library
+  homepage: https://TomographicImaging.github.io/CIL
diff --git a/recipe/bld.bat b/recipe/bld.bat
deleted file mode 100644
index 97fb90517..000000000
--- a/recipe/bld.bat
+++ /dev/null
@@ -1,8 +0,0 @@
-ROBOCOPY /E "%RECIPE_DIR%\.." "%SRC_DIR%" /XD .git /XD Wrappers\Python\build
-
-set SETUPTOOLS_SCM_PRETEND_VERSION_FOR_CIL=%PKG_VERSION%
-if not "%GIT_DESCRIBE_NUMBER%"=="0" (
-    set SETUPTOOLS_SCM_PRETEND_VERSION_FOR_CIL=%PKG_VERSION%.dev%GIT_DESCRIBE_NUMBER%+%GIT_DESCRIBE_HASH%
-)
-pip install . --no-deps
-if errorlevel 1 exit 1
diff --git a/recipe/build.sh b/recipe/build.sh
deleted file mode 100755
index 93f548655..000000000
--- a/recipe/build.sh
+++ /dev/null
@@ -1,16 +0,0 @@
-#!/usr/bin/env bash
-set -euxo pipefail
-
-extra_args="-G Ninja"
-if test $(python -c "from __future__ import print_function; import platform; print(platform.system())") = Darwin ; then
-  echo "Darwin"
-  extra_args="$extra_args -DOPENMP_LIBRARIES=${CONDA_PREFIX}/lib -DOPENMP_INCLUDES=${CONDA_PREFIX}/include"
-else
-  echo "Not Darwin"
-fi
-
-export SETUPTOOLS_SCM_PRETEND_VERSION_FOR_CIL="${PKG_VERSION}"
-if test "${GIT_DESCRIBE_NUMBER}" != "0"; then
-  export SETUPTOOLS_SCM_PRETEND_VERSION_FOR_CIL="${PKG_VERSION}.dev${GIT_DESCRIBE_NUMBER}+${GIT_DESCRIBE_HASH}"
-fi
-pip install . --no-deps -Ccmake.args="${extra_args}"
diff --git a/recipe/meta.yaml b/recipe/meta.yaml
deleted file mode 100644
index 1845868dc..000000000
--- a/recipe/meta.yaml
+++ /dev/null
@@ -1,78 +0,0 @@
-package:
-  name: cil
-  version: {{ environ.get('GIT_DESCRIBE_TAG','v')[1:].split('-')[0] }}
-
-source:
-  path: ..
-
-build:
-  preserve_egg_dir: False
-  number: {{ GIT_DESCRIBE_NUMBER }}
-
-test:
-  requires:
-    - pip
-    - python-wget
-    - cvxpy!=1.8.2                   # [linux]
-    - scikit-image
-    - tomophantom 3.0.3
-    - tigre 2.6
-    - packaging
-    - ccpi-regulariser 24.0.1 # [not osx]
-    - astra-toolbox 2.1 {{ 'cuda*' if environ.get('TESTS_FORCE_GPU', '') else 'py*' }}
-    - matplotlib-base >=3.3
-    - zenodo_get >=1.6
-    - dxchange >= 0.2.1
-    - olefile >=0.46
-
-  source_files:
-    - ./Wrappers/Python/test
-
-  commands:
-    - pip install unittest-parametrize
-    - python -m unittest discover -v -s Wrappers/Python/test
-
-{% set ipp_version = '2021.12' %}
-
-requirements:
-  build:
-    - cmake >=3.16
-    - ninja
-    - {{ compiler('cxx') }}
-
-  host:
-    - libgomp      # [linux]
-    - llvm-openmp  # [osx]
-    - ipp-include {{ ipp_version }}
-    - ipp-devel {{ ipp_version }}
-    - python x.x
-    - pip
-    - setuptools >=64
-    - setuptools_scm >=8
-    - scikit-build-core >=0.10
-
-  run:
-    - {{ pin_compatible('python', min_pin='x.x') }}
-    - ipp {{ ipp_version }}
-    - numpy >=1.23,<2
-    - scipy >=1.4
-    - h5py
-    - pillow
-    - pywavelets
-    - cil-data >=22
-    - tqdm
-    - numba
-
-  # version constraints of optional dependencies
-  run_constrained:
-    - tomophantom >=3.0.3
-    - astra-toolbox >=1.9.9.dev5
-    - tigre >=2.4
-    - ccpi-regulariser >=24.0.1
-    - olefile >=0.46
-    - zenodo_get >=1.6
-
-about:
-  home: https://TomographicImaging.github.io/CIL
-  license:  Apache 2.0 License
-  summary: 'CCPi Core Imaging Library'

From db60f2288ee7772095252f0a934647de39373efa Mon Sep 17 00:00:00 2001
From: Casper da Costa-Luis <casper.dcl@physics.org>
Date: Thu, 7 May 2026 16:30:13 +0100
Subject: [PATCH 3/6] build: fix dependenies

- fixes #2209
---
 CHANGELOG.md   | 3 ++-
 pyproject.toml | 5 ++---
 recipe.yaml    | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ace85d0e6..35200f143 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,7 +11,8 @@
     - Fixed behaviour of `ZeissDataReader` when negative values are passed in the ROI (#2244)
     - Fix `show2D` truncating plots when count is not a multiple of `num_cols` (#2315)
   - Dependencies:
-    - olefile and dxchange are optional dependencies, instead of required (#2209)
+    - `olefile` and `dxchange` are optional dependencies, instead of required (#2209, #2321)
+    - fix missing `packaging` required dependency (#2321)
     - dxchange minimum version set to 0.2.1 to fix #2256 (#2268)
     - improve `tqdm` notebook support (#2241)
     - cvxpy version set to !=1.8.2 to fix #2303 (#2306)
diff --git a/pyproject.toml b/pyproject.toml
index 6a811758f..d06683005 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,12 +42,10 @@ readme = "README.md"
 keywords = ["tomography", "optimisation"]
 dependencies = [
     #"cil-data>=22", # missing from PyPI
-    "dxchange>=0.2.1",  # Minimal release for OLE dtype fix: https://github.com/data-exchange/dxchange/pull/124#issue-3828961474
     "h5py",
     #"ipp==2021.12.*", # PyPI conflicts with conda package
     "numba",
     "numpy>=1.23, <2.0.0",
-    "olefile>=0.46",
     "pillow",
     "pywavelets",
     "scipy>=1.4.0",
@@ -57,6 +55,8 @@ dependencies = [
 [project.optional-dependencies]
 plugins = [
     "ipywidgets",
+    "dxchange>=0.2.1",
+    "olefile>=0.46",
     #"tomophantom==2.0.0", # [linux] # missing from PyPI
 ]
 gpu = [
@@ -68,7 +68,6 @@ test = [
     #"ccpi-regulariser=24.0.1", # [not osx] # missing from PyPI
     "cvxpy",
     "matplotlib-base>=3.3",
-    "packaging",
     "scikit-image",
     "unittest-parametrize",
     "wget",
diff --git a/recipe.yaml b/recipe.yaml
index be805de36..db40f657b 100644
--- a/recipe.yaml
+++ b/recipe.yaml
@@ -53,6 +53,7 @@ requirements:
     - scikit-build-core >=0.10
   run:
     - python >=${{ python_min }}
+    - packaging
     - if: x86_64
       then: ipp ${{ ipp_version }}
     - numpy >=1.23,<2
@@ -93,7 +94,6 @@ tests:
         - if: linux
           then: cvxpy !=1.8.2
         - scikit-image
-        - packaging
         - tomophantom 3.0.3.*
         - if: not osx
           then: ccpi-regulariser 24.0.1.*

From 83796a73d4d04bac438f31c0245b454c340a04d0 Mon Sep 17 00:00:00 2001
From: Casper da Costa-Luis <casper.dcl@physics.org>
Date: Thu, 7 May 2026 16:48:02 +0100
Subject: [PATCH 4/6] CI: native test matrix

---
 .github/workflows/build.yml | 107 +++++++++++++++---------------------
 recipe.yaml                 |   8 +--
 2 files changed, 45 insertions(+), 70 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7f53bd489..706ef6c7f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -60,34 +60,14 @@ jobs:
         sed -i '/${{ steps.reqs.outputs.envname }}/d' ~/.profile
         source ~/.profile
         conda env remove -n "${{ steps.reqs.outputs.envname }}"
-  test:
-    defaults: {run: {shell: 'bash -el {0}'}}
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        include:
-        - {python-version: '3.10', numpy-version: 1.23}
-        - {python-version: 3.12, numpy-version: 1.26}
-    steps:
-    - uses: actions/checkout@v6
-      with: {fetch-depth: 0, submodules: recursive}
-    - name: set requirements
-      run: sed -ri -e '/ python /d' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' -e 's/cuda*//' -e '/tigre/d' scripts/cil_development.yml
-    - uses: conda-incubator/setup-miniconda@v4
-      with:
-        python-version: ${{ matrix.python-version }}
-        environment-file: scripts/cil_development.yml
-        activate-environment: cil_dev
-    - run: pip install .
-    - name: test
-      run: python -m unittest discover -v ./Wrappers/Python/test
-  conda-matrix:
-    runs-on: ubuntu-latest
+  test-matrix:
+    runs-on: ubuntu-slim
     outputs:
       python-version: ${{ steps.matrix.outputs.python-version }}
       numpy-version: ${{ steps.matrix.outputs.numpy-version }}
       os: ${{ steps.matrix.outputs.os }}
-      include-numpy: ${{ steps.matrix.outputs.include-numpy }}
+      include: ${{ steps.matrix.outputs.include }}
+      conda-include: ${{ steps.matrix.outputs.conda-include }}
     steps:
     - id: matrix
       run: |
@@ -108,16 +88,42 @@ jobs:
           fi
         fi
         if $include_max; then
-          echo "include-numpy=[{'python-version': 3.12, 'numpy-version': 1.26, 'os': 'ubuntu'}, {'python-version': 3.12, 'numpy-version': 1.26, 'os': 'windows'}]" >> $GITHUB_OUTPUT
+          echo "include=[{'os': 'ubuntu', 'python-version': 3.12, 'numpy-version': 1.26}, {'os': 'windows', 'python-version': 3.12, 'numpy-version': 1.26}]" >> $GITHUB_OUTPUT
+          echo "conda-include=[{'os': 'ubuntu', 'python-version': 3.12}, {'os': 'windows', 'python-version': 3.12}]" >> $GITHUB_OUTPUT
         else
-          echo "include-numpy=[]" >> $GITHUB_OUTPUT
+          echo "include=[]" >> $GITHUB_OUTPUT
         fi
-  conda-build:
+  test:
+    defaults: {run: {shell: 'bash -el {0}'}}
+    runs-on: ${{ matrix.os }}-${{ matrix.os == 'ubuntu' && '24.04' || '2022' }}
+    needs: test-matrix
+    strategy:
+      matrix:
+        os: ${{ fromJson(needs.test-matrix.outputs.os) }}
+        python-version: ${{ fromJson(needs.test-matrix.outputs.python-version) }}
+        numpy-version: ${{ fromJson(needs.test-matrix.outputs.numpy-version) }}
+        include: ${{ fromJson(needs.test-matrix.outputs.include) }}
+    steps:
+    - uses: actions/checkout@v6
+      with: {fetch-depth: 0, submodules: recursive}
+    - name: set requirements
+      run: sed -ri -e '/ python /d' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' -e 's/cuda*//' -e '/tigre/d' scripts/cil_development.yml
+    - uses: conda-incubator/setup-miniconda@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+        environment-file: scripts/cil_development.yml
+        activate-environment: cil_dev
+    - run: pip install .
+    - name: test
+      run: python -m unittest discover -v ./Wrappers/Python/test
+  conda-build-test:
     runs-on: ${{ matrix.os }}-${{ matrix.os == 'ubuntu' && '24.04' || '2022' }}
-    needs: conda-matrix
+    needs: test-matrix
     strategy:
       matrix:
-        os: ${{ fromJson(needs.conda-matrix.outputs.os) }}
+        os: ${{ fromJson(needs.test-matrix.outputs.os) }}
+        python-version: ${{ fromJson(needs.test-matrix.outputs.python-version) }}
+        include: ${{ fromJson(needs.test-matrix.outputs.conda-include) }}
     steps:
     - uses: actions/checkout@v6
       with:
@@ -129,46 +135,19 @@ jobs:
     - uses: prefix-dev/rattler-build-action@v0.2.37
       with:
         recipe-path: recipe.yaml
-        build-args: --experimental -c conda-forge -c https://software.repos.intel.com/python/conda -c ccpi --no-test
-        artifact-name: conda-${{ matrix.os }}
-  conda-test:
-    defaults: {run: {shell: 'bash -el {0}'}}
-    runs-on: ${{ matrix.os }}-${{ matrix.os == 'ubuntu' && '24.04' || '2022' }}
-    needs: [conda-matrix, conda-build]
-    strategy:
-      matrix:
-        python-version: ${{ fromJson(needs.conda-matrix.outputs.python-version) }}
-        numpy-version: ${{ fromJson(needs.conda-matrix.outputs.numpy-version) }}
-        os: ${{ fromJson(needs.conda-matrix.outputs.os) }}
-        include: ${{ fromJson(needs.conda-matrix.outputs.include-numpy) }}
-    steps:
-    - uses: actions/checkout@v6
-    - uses: conda-incubator/setup-miniconda@v4
-      with:
-        python-version: ${{ matrix.python-version }}
-        mamba-version: "*"
-        channels: conda-forge
-        conda-remove-defaults: "true"
-    - run: conda install conda-build
-    - uses: actions/download-artifact@v8
-      with:
-        name: conda-${{ matrix.os }}
-        path: output
-    - name: conda test
-      run: >
-        conda build -c conda-forge  -c https://software.repos.intel.com/python/conda -c ccpi --override-channels --python=${{ matrix.python-version }}
-        --test output/*/cil-* --extra-deps numpy=${{ matrix.numpy-version }}
+        build-args: --experimental -c conda-forge -c https://software.repos.intel.com/python/conda -c ccpi --variant python=${{ matrix.python-version }}
+        artifact-name: conda-py${{ matrix.python-version }}-${{ matrix.os }}
   conda-upload:
     if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags')
-    defaults: {run: {shell: 'bash -el {0}', working-directory: output}}
-    runs-on: ubuntu-latest
-    needs: conda-test
+    defaults: {run: {working-directory: output}}
+    runs-on: ubuntu-slim
+    needs: conda-build-test
     steps:
     - uses: actions/checkout@v6
     - uses: prefix-dev/rattler-build-action@v0.2.37
       with: {setup-only: true}
     - uses: actions/download-artifact@v8
-      with: {pattern: conda-*, path: output, merge-multiple: true}
+      with: {pattern: conda-py*-*, path: output, merge-multiple: true}
     - name: conda upload -c ccpi
       run: >
         rattler-build upload anaconda */*.conda -f
@@ -290,6 +269,6 @@ jobs:
         tags: ${{ steps.meta.outputs.tags }}
         labels: ${{ steps.meta.outputs.labels }}
   pass:
-    needs: [test-cuda, test, conda-test, docs, docker]
-    runs-on: ubuntu-latest
+    needs: [test-cuda, test, conda-build-test, docs, docker]
+    runs-on: ubuntu-slim
     steps: [{run: echo success}]
diff --git a/recipe.yaml b/recipe.yaml
index db40f657b..f184f4eae 100644
--- a/recipe.yaml
+++ b/recipe.yaml
@@ -2,7 +2,6 @@ schema_version: 1
 
 context:
   name: ${{ load_from_file("pyproject.toml").project.name }} # ratter-build --experimental
-  python_min: ${{ load_from_file("pyproject.toml")['project']['requires-python'] | replace(">=", "") }} # ratter-build --experimental
   build_number: 0
   version: ${{ git.latest_tag(".") | replace("v", "") }} # .dev${{ build_number }}+g${{ git.head_rev(".") }} # ratter-build --experimental
   test_gpu: ${{ env.get("TESTS_FORCE_GPU", default="") | bool }}
@@ -19,7 +18,6 @@ source:
 
 build:
   number: ${{ build_number }}
-  noarch: python
   script:
     content:
       - if: win
@@ -46,13 +44,13 @@ requirements:
       then:
       - ipp-include ${{ ipp_version }}
       - ipp-devel ${{ ipp_version }}
-    - python ${{ python_min ~ '.*' }}
+    - python
     - pip
     - setuptools >=64
     - setuptools_scm >=8
     - scikit-build-core >=0.10
   run:
-    - python >=${{ python_min }}
+    - python
     - packaging
     - if: x86_64
       then: ipp ${{ ipp_version }}
@@ -79,8 +77,6 @@ tests:
         - cil
         - cil.framework
         - cil.version
-      pip_check: false
-      python_version: ["${{ python_min ~ '.*' }}", "3.*"]
   - script:
       - pip install unittest-parametrize
       - python -m unittest discover -v -s Wrappers/Python/test

From c5da95029d5fe70a87a9cda66d06b9b561f5834a Mon Sep 17 00:00:00 2001
From: Casper da Costa-Luis <casper.dcl@physics.org>
Date: Thu, 7 May 2026 17:58:50 +0000
Subject: [PATCH 5/6] CI: speed up setup-miniconda

---
 .github/workflows/build.yml | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 706ef6c7f..58f4604f9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -41,8 +41,11 @@ jobs:
     - uses: conda-incubator/setup-miniconda@v4
       with:
         python-version: ${{ matrix.python-version }}
-        environment-file: scripts/cil_development.yml
+        use-mamba: true
+        mamba-version: "*"
+        channels: conda-forge
         activate-environment: ${{ steps.reqs.outputs.envname }}
+        environment-file: scripts/cil_development.yml
         run-post: false
     - id: build
       name: build
@@ -107,12 +110,15 @@ jobs:
     - uses: actions/checkout@v6
       with: {fetch-depth: 0, submodules: recursive}
     - name: set requirements
-      run: sed -ri -e '/ python /d' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' -e 's/cuda*//' -e '/tigre/d' scripts/cil_development.yml
+      run: sed -ri -e 's/(.* python) .*/\1=${{ matrix.python-version }}/' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' -e 's/cuda*//' -e '/tigre/d' scripts/cil_development.yml
     - uses: conda-incubator/setup-miniconda@v4
       with:
-        python-version: ${{ matrix.python-version }}
-        environment-file: scripts/cil_development.yml
+        miniforge-version: latest
+        use-mamba: true
+        mamba-version: "*"
+        channels: conda-forge
         activate-environment: cil_dev
+        environment-file: scripts/cil_development.yml
     - run: pip install .
     - name: test
       run: python -m unittest discover -v ./Wrappers/Python/test
@@ -172,10 +178,12 @@ jobs:
         ref: ${{ github.event.pull_request.head.sha || github.ref }} # fix SHA
     - uses: conda-incubator/setup-miniconda@v4
       with:
+        miniforge-version: latest
+        use-mamba: true
         python-version: 3.12
         mamba-version: "*"
         channels: conda-forge
-        conda-remove-defaults: "true"
+        conda-remove-defaults: true
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: '3.2'
@@ -184,7 +192,7 @@ jobs:
     - name: install dependencies
       run: |
         mamba install -c conda-forge -yq conda-merge
-        sed -ri -e 's/cuda*//' -e '/tigre/d' ../scripts/cil_development.yml
+        sed -ri -e 's/(.* python) .*/\1=3.12/' -e 's/cuda*//' -e '/tigre/d' ../scripts/cil_development.yml
         conda-merge ../scripts/cil_development.yml docs_environment.yml > environment.yml
         mamba env update -n test --file environment.yml
         conda list

From be7811b0d639a052d82193f74e14cd83a82a836e Mon Sep 17 00:00:00 2001
From: Casper da Costa-Luis <casper.dcl@physics.org>
Date: Fri, 8 May 2026 16:23:13 +0000
Subject: [PATCH 6/6] force non-cuda astra where appropriate

- follow-up to #2323
---
 .github/workflows/build.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 58f4604f9..343038a24 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -110,7 +110,7 @@ jobs:
     - uses: actions/checkout@v6
       with: {fetch-depth: 0, submodules: recursive}
     - name: set requirements
-      run: sed -ri -e 's/(.* python) .*/\1=${{ matrix.python-version }}/' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' -e 's/cuda*//' -e '/tigre/d' scripts/cil_development.yml
+      run: sed -ri -e 's/(.* python) .*/\1=${{ matrix.python-version }}/' -e 's/(.* numpy) .*/\1=${{ matrix.numpy-version }}/' -e 's/cuda*/py*/' -e '/tigre/d' scripts/cil_development.yml
     - uses: conda-incubator/setup-miniconda@v4
       with:
         miniforge-version: latest
@@ -192,7 +192,7 @@ jobs:
     - name: install dependencies
       run: |
         mamba install -c conda-forge -yq conda-merge
-        sed -ri -e 's/(.* python) .*/\1=3.12/' -e 's/cuda*//' -e '/tigre/d' ../scripts/cil_development.yml
+        sed -ri -e 's/(.* python) .*/\1=3.12/' -e 's/cuda*/py*/' -e '/tigre/d' ../scripts/cil_development.yml
         conda-merge ../scripts/cil_development.yml docs_environment.yml > environment.yml
         mamba env update -n test --file environment.yml
         conda list