I have just pushed a massive change to petsc-dev. All destructor functions of the form XXXDestroy(XXX) are now XXXDestroy(XXX*), so for example KSPDestroy(ksp) should be replaced with KSPDestroy(&ksp). This has no effect on Fortran codes that remain the same. I have tested with C and C++ but likely missed a few instances. To avoid dealing with this change immediately you can do hg pull hg update d3e10315d68b to work with the last version before this change, then when you are ready to update do another hg pull hg update If you are actually changing PETSc code then you cannot delay doing the full update. Please report all problems to [email protected] or [email protected] Barry To update your code quickly in emacs you can make a tags file for your source by, for example, etags *.c then in emacs do meta visit-tags-table CR CR which loads the tags file and then meta tags-query CR Destroy(\([a-zA-Z]\) CR Destroy(&\1 where CR means hit carriage return