for PETSc v3.16.0
C codes (Chapters 1--12) were tested with PETSc v3.16.0 and v3.16.1 (main branch, commit 680c40f5)
Python codes (Chapters 13--14) were tested with Firedrake commit 9ce1619d
Gmsh version 4.6.0.
Test machine: bueler-thelio ubuntu 20.04