Merge branch 'ylecornec/check_opam_switch-compatible' into ylecornec/…

…check_opam_switch-develop

Makefile

@@ -70,6 +70,9 @@ ocaml_version:
 ocaml_word_size:
 	@if ! ocamlopt -config | grep "word_size:" | grep $(WORD_SIZE); then echo "invalid machine word size, expected $(WORD_SIZE)" ; exit 1; fi
 
+
+# Checks that the current opam switch contains the packages from opam.export at the same version.
+# This check is disabled in the pure nix environment (that does not use opam).
 check_opam_switch:
 ifneq ($(DISABLE_CHECK_OPAM_SWITCH), true)
 	check_opam_switch opam.export

README-dev.md

@@ -50,8 +50,8 @@ Refer to [/dev](/dev).
 
 Mina has a variety of opam and system dependencies.
 
-To get all the opam dependencies you need, you run `opam switch import
-opam.export`.
+To get all the opam dependencies you need, you run `opam switch import opam.export`.
+> *_NOTE:_*  The switch provides a `dune_wrapper` binary that you can use instead of dune, and will fail early if your switch becomes out of sync with the `opam.export` file.
 
 Some of our dependencies aren't taken from `opam`, and aren't integrated
 with `dune`, so you need to add them manually, by running `scripts/pin-external-packages.sh`.