fixup

Author: connorjward

.github/workflows/build.yml

@@ -66,6 +66,11 @@ jobs:
           # shellcheck disable=SC2086
           ./firedrake/scripts/firedrake-install \
             $COMPLEX \
+            --mpicc="$MPICH_DIR"/mpicc \
+            --mpicxx="$MPICH_DIR"/mpicxx \
+            --mpif90="$MPICH_DIR"/mpif90 \
+            --mpiexec="$MPICH_DIR"/mpiexec \
+            --mpihome="$MPICH_DIR"/.. \
             --venv-name firedrake_venv \
             --no-package-manager \
             --disable-ssh \