Dear firedrakers, some of you attempting to install or update recently may have seen that the PETSc build fails (attempting to install Eigen). This is a reported bug in the PETSc installer, we hope that it will be fixed in the next day or so. As a short-term workaround, you can disable the installation of Eigen when running firedrake-install or firedrake-update like so: $ PETSC_CONFIGURE_OPTIONS="--download-eigen=0" firedrake-install or $ PETSC_CONFIGURE_OPTIONS="--download-eigen=0" firedrake-update This will disable the ability to solve problems using hybridisation methods, but Firedrake will otherwise be functional. A subsequent call to firedrake-install or firedrake-update without setting PETSC_CONFIGURE_OPTIONS will subsequently download and install Eigen, you can do this when the problem is fixed. I will update this thread when the bug fix arrives in PETSc and we have confirmed it works for us. Thanks, and apologies for any problems this might be causing, Lawrence