use old numpy version for old macos

.github/workflows/ci.yml

@@ -29,8 +29,10 @@ jobs:
             python-version: 3.7
         include:
           - os: ubuntu-20.04
+            NUMPY_VERSION: ">=2"
             INSTALL_DEPS: sudo apt-get update && sudo apt-get -y install gfortran-7 swig libopenmpi-dev openmpi-bin libopenblas-dev && sudo ln -s `which gfortran-7` /usr/local/bin/gfortran
           - os: macos-latest
+            NUMPY_VERSION: ">=2"
             # Different versions of homebrew put the gfortran in different
             INSTALL_DEPS: >
               brew update-reset 
@@ -48,6 +50,7 @@ jobs:
               ; fi
               && echo "gfortran now at $(which -a gfortran)"
           - os: macos-13
+            NUMPY_VERSION: "<2"
             # Different versions of homebrew put the gfortran in different
             INSTALL_DEPS: >
               brew update-reset 
@@ -84,13 +87,14 @@ jobs:
     - name: Install python dependencies
       run: |
         python -m pip install --upgrade pip
+        pip install "numpy${{ matrix.NUMPY_VERSION }}"
         pip install -v .
         pip install --no-binary=mpi4py mpi4py astropy pytest pytest-cov getdist
 
     - name: Install PocoMC
       if: matrix.python-version != '3.7'
       run: |
-        pip install pocomc==1.2.2
+        pip install pocomc==1.2.6
 
     - name: Test nautilus alone
       if: (matrix.python-version == '3.12' || matrix.python-version == '3.11' || matrix.python-version =='3.10') && (matrix.os == 'macos-13')