for PETSc v3.18.0 and v3.18.1
C codes (Chapters 1--12) were tested with PETSc v3.18.0 (commit 54841b124fc) and v3.18.1 (commit 08ba72b19cc)
Python codes (Chapters 13--14) were tested with Firedrake commit 729b7b4f1b
Gmsh version 4.9.3 (and 4.9.0)
Test machine: thelio ubuntu 20.04