Debugging conda mamba env setup pt 7

Trying three different ways of installing mamba/micromamba,
in the hope that at least one of them currenlty works.
This is such a shitshow.

.github/workflows/ci.yaml

@@ -42,10 +42,12 @@ jobs:
         os:
           - ubuntu-latest
           # - macos-latest
-          # - ubuntu-22.04
           # - ubuntu-20.04
+          # - ubuntu-22.04
+          # - ubuntu-24.04
           # - macos-12
-          # - macos-11
+          # - macos-13
+          # - macos-14
 
         # Test cases as listed in test/cases/*.txt
         # We update them automatically when running the test/run.sh script, so that each time
@@ -104,13 +106,15 @@ jobs:
           # For now, we just test the base case to see if it's generally working.
           # This repeats one of the Ubuntu runs for the base case, but that's okay
           # to keep it future proof when the default ubuntu-latest changes.
+          - os: ubuntu-20.04
+            case: base
           - os: ubuntu-22.04
             case: base
-          - os: ubuntu-20.04
+          - os: ubuntu-24.04
             case: base
           - os: macos-12
             case: base
-          - os: macos-11
+          - os: macos-13
             case: base
 
     # -------------------------------------------------------
@@ -122,27 +126,30 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup Conda
-        uses: conda-incubator/setup-miniconda@v3.0.3
+        uses: conda-incubator/setup-miniconda@v3.0.4
         with:
           # We need mamba here already, otherwise we run into
           # https://github.com/conda-incubator/setup-miniconda/issues/262
-          # mamba-version: "*"
-          # channels: conda-forge
-          # We need to replace the above, at least for now, due to instabilities in the action,
+          mamba-version: "*"
+          python-version: 3.12
+          channels: conda-forge,defaults
+          channel-priority: true
+          use-mamba: true
+          environment-file: envs/grenepipe.yaml
+          activate-environment: grenepipe
+
+          # We might need to replace the above, at least for now, due to instabilities in the action,
           # see https://github.com/conda-incubator/setup-miniconda/issues/274#issue-1531425010
           # If that changes again in the future, also change it below in the other jobs.
           # miniforge-variant: Mambaforge
-          miniforge-version: latest
+          # miniforge-version: latest
           # New workaround suggestion:
           # https://github.com/conda-incubator/setup-miniconda/issues/292#issuecomment-1767669652
           # Why is this stuff so broken all the time?
-          use-mamba: true
-          channels: conda-forge
-          environment-file: envs/grenepipe.yaml
-          activate-environment: grenepipe
 
       # Manually create the conda env.
-      # Not needed at the moment, as the above setup works fine. Keeping this here for reference.
+      # Not needed at the moment, as the above setup works (if it works).
+      # Keeping this here for reference.
       # - name: Install Conda Env
       #   shell: bash -el {0}
       #   run: |
@@ -223,10 +230,10 @@ jobs:
           # mamba-version: "*"
           # channels: conda-forge
           # Need to use a different setup to get mamba to work, see above.
-          # miniforge-variant: Mambaforge
+          miniforge-variant: Mambaforge
           miniforge-version: latest
           use-mamba: true
-          channels: conda-forge
+          channels: conda-forge,defaults
           environment-file: envs/grenepipe.yaml
           activate-environment: grenepipe
 
@@ -266,16 +273,19 @@ jobs:
 
       matrix:
         os:
-          - ubuntu-22.04
           - ubuntu-20.04
+          - ubuntu-22.04
+          - ubuntu-24.04
           - macos-12
-          - macos-11
+          - macos-13
+          - macos-14
 
         installer:
           # Conda is just waaaay to slow... some runs even exceed the GitHub Actions
           # max runtime of 6h, so we have to deactivate it for now.
           # - conda
           - mamba
+          - micromamba
 
     # -------------------------------------------------------
     #     Steps
@@ -286,19 +296,18 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup Conda
-        uses: conda-incubator/setup-miniconda@v3.0.3
+        uses: mamba-org/setup-micromamba@v1.9.0
         with:
-          # mamba-version: "*"
-          # channels: conda-forge
-          # Need to use a different setup now to get mamba to work, see above.
-          # miniforge-variant: Mambaforge
-          miniforge-version: latest
-          use-mamba: true
-          channels: conda-forge
+          # Trying another installer, see if that one finally works...
+          # Any version from https://github.com/mamba-org/micromamba-releases
+          micromamba-version: '1.5.8-0'
           environment-file: envs/grenepipe.yaml
-          activate-environment: grenepipe
+          environment-name: grenepipe
+          init-shell: bash
+          post-cleanup: 'all'
 
       - name: Install Envs
+        shell: bash -el {0}
         run: |
           cd envs
           for env in `ls *.yaml` ; do