Coq 8.7 has a few incompatibilities with 8.6. We list the main sources of changes

• Change in the representation of constants in library Reals
  • Typical consequences: 4 is not any more 2*2, 3 is not any more 2+1, -1 is now different from -(1)
  • expressions of the form (-x)%R hide a non-simplifiable coercion IZR; they do not simplify anymore; instead unfold IZR; rewrite <- INR_IPR
  • auto with real now solve all inequations between constants (e.g. 5<=7)
• Fix of rewrite ... in *

There are may changes documented in dev/doc/changes.txt. The one empirically requiring the most updating are the following:

• New level of abstraction EConstr, documented in dev/doc/econstr.md. Typical changes to do in plugins:
  • replacing open Term with open EConstr
  • add a sigma to various functions now expecting it, e.g dependent (for old-style goals, get a sigma with Tacmach.project)
  • replacing kind_of_term with kind sigma
  • replacing Constr.equal with EConstr.eq_constr sigma
  • change pr_lconstr into pr_leconstr
  • change fold_constr with for_constr sigma
• Few changes in the representation of constr_expr and related
  • CLetIn has now an explicit argument for the optional type
  • LocalRawAssum and LocalRawDef are now CLocalAssum and CLocalDef