Raise MSRV to 1.40.0

This will shortly be needed for Fuchsia support.

Author: asomers

.cirrus.yml

@@ -12,7 +12,7 @@ task:
     image: freebsd-11-4-release-amd64
   setup_script:
     - fetch https://sh.rustup.rs -o rustup.sh
-    - sh rustup.sh -y --profile=minimal --default-toolchain 1.36.0
+    - sh rustup.sh -y --profile=minimal --default-toolchain 1.40.0
     - $HOME/.cargo/bin/rustup target add i686-unknown-freebsd
   amd64_test_script:
     - . $HOME/.cargo/env
@@ -42,7 +42,7 @@ task:
     image: catalina-xcode
   setup_script:
     - curl --proto '=https' --tlsv1.2 -sSf -o rustup.sh https://sh.rustup.rs
-    - sh rustup.sh -y --profile=minimal --default-toolchain 1.36.0
+    - sh rustup.sh -y --profile=minimal --default-toolchain 1.40.0
     - . $HOME/.cargo/env
     - bash ci/install.sh
   script:
@@ -92,7 +92,7 @@ docker_builder:
   setup_script:
     - mkdir /tmp/home
     - curl --proto '=https' --tlsv1.2 -sSf -o rustup.sh https://sh.rustup.rs
-    - sh rustup.sh -y --profile=minimal --default-toolchain 1.36.0
+    - sh rustup.sh -y --profile=minimal --default-toolchain 1.40.0
     - . $HOME/.cargo/env
     - bash ci/install.sh
   script:
@@ -110,11 +110,11 @@ task:
     - name: Linux x86_64
       env:
         TARGET: x86_64-unknown-linux-gnu
-        TOOLCHAIN: 1.36.0
+        TOOLCHAIN: 1.40.0
     - name: Linux x86_64 musl
       env:
         TARGET: x86_64-unknown-linux-musl
-        TOOLCHAIN: 1.36.0
+        TOOLCHAIN: 1.40.0
   container:
     image: rust:1.36
   setup_script:

CHANGELOG.md

@@ -10,6 +10,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 ### Changed
 
+- Minimum supported Rust version is now 1.40.0.
+  ([#1356](https://github.com/nix-rust/nix/pull/1356))
+
 - i686-apple-darwin has been demoted to Tier 2 support, because it's deprecated
   by Xcode.
   (#[1350](https://github.com/nix-rust/nix/pull/1350))

README.md

@@ -86,7 +86,7 @@ Tier 3:
 
 ## Usage
 
-`nix` requires Rust 1.36.0 or newer.
+`nix` requires Rust 1.40.0 or newer.
 
 To use `nix`, add this to your `Cargo.toml`: