[deps] Pin version of Why3

caisar.opam

@@ -27,7 +27,7 @@ depends: [
   "yojson" {>= "1.7.0"}
   "menhirLib" {>= "20210310"}
   "csv" {>= "2.4"}
-  "why3" {>= "1.6.0"}
+  "why3" {= "1.6.0"}
   "re" {>= "1.10.4"}
   "fpath" {>= "0.7.3"}
   "yaml" {>= "3.1.0"}

dune-project

@@ -35,7 +35,7 @@
    (yojson (>= 1.7.0))
    (menhirLib (>= 20210310))
    (csv (>= 2.4))
-   (why3 (>= 1.6.0))
+   (why3 (= 1.6.0))
    (re (>= 1.10.4))
    (fpath (>= 0.7.3))
    (yaml (>= 3.1.0))