Would it work with 1.64

Author: bluss

.github/workflows/ci.yaml

@@ -50,7 +50,7 @@ jobs:
           - stable
           - beta
           - nightly
-          - 1.70.0  # MSRV
+          - 1.64.0  # MSRV
 
     name: tests/${{ matrix.rust }}
     steps:

Cargo.toml

@@ -3,7 +3,7 @@
 name = "ndarray"
 version = "0.15.6"
 edition = "2018"
-rust-version = "1.70"
+rust-version = "1.64"
 authors = [
   "Ulrik Sverdrup \"bluss\"",
   "Jim Turner"

xtest-serialization/Cargo.toml

@@ -21,9 +21,14 @@ default-features = false
 [dev-dependencies.serde_json]
 version = "1.0.40"
 
+[dev-dependencies.rmp]
+# Old version to work with Rust 1.64+
+version = "=0.8.10"
+
 [dev-dependencies.rmp-serde]
-version = "0.14.0"
+# Old version to work with Rust 1.64+
+version = "0.14"
 
 [dependencies.ron]
-version = "0.5.1"
+version = "0.8.1"
 optional = true