diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index cb1e25c..39a8ba2 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -85,18 +85,18 @@ jobs:
     - name: Install homebrew dependencies
       if: matrix.os == 'macos-12'
       run: |
-        brew install gcc@12 llvm boost fftw hdf5 open-mpi openblas
+        brew install ccache gcc@12 llvm boost fftw hdf5 open-mpi openblas
         brew install wentzell/triqs/nfft
-        pip3 install mako numpy scipy mpi4py
-        pip3 install -r requirements.txt
+        mkdir $HOME/.venv
+        python3 -m venv $HOME/.venv/my_python
+        source $HOME/.venv/my_python/bin/activate
+        pip install mako numpy scipy mpi4py
+        pip install -r requirements.txt
         echo "FC=gfortran-13" >> $GITHUB_ENV
         echo "BLAS_ROOT=$(brew --prefix)/opt/openblas" >> $GITHUB_ENV
         echo "LAPACK_ROOT=$(brew --prefix)/opt/openblas" >> $GITHUB_ENV
-
-    - name: add clang cxxflags
-      if: ${{ contains(matrix.cxx, 'clang') }}
-      run:
-        echo "CXXFLAGS=-stdlib=libc++" >> $GITHUB_ENV
+        echo "VIRTUAL_ENV=$VIRTUAL_ENV" >> $GITHUB_ENV
+        echo "PATH=$PATH" >> $GITHUB_ENV
 
     - name: add clang cxxflags
       if: ${{ contains(matrix.cxx, 'clang') }}