Auto merge of #2175 - RalfJung:xargo, r=oli-obk

bump Xargo

Also use that as a clue to refresh our CI caches.

Fixes https://github.com/rust-lang/miri/issues/705

.github/workflows/ci.yml

@@ -46,7 +46,8 @@ jobs:
       # we cannot reuse anyway when the nightly changes (and it grows quite large
       # over time).
       - name: Add cache for cargo
-        uses: actions/cache@v2
+        id: cache
+        uses: actions/cache@v3
         with:
           path: |
             # Taken from <https://doc.rust-lang.org/nightly/cargo/guide/cargo-home.html#caching-the-cargo-home-in-ci>.
@@ -57,10 +58,11 @@ jobs:
             # contains package information of crates installed via `cargo install`.
             ~/.cargo/.crates.toml
             ~/.cargo/.crates2.json
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}-xargo0.3.25
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock', 'cargo-miri/version.rs') }}
           restore-keys: ${{ runner.os }}-cargo
 
       - name: Install rustup-toolchain-install-master and xargo
+        if: ${{ steps.cache.outputs.cache-hit == 'false' }}
         shell: bash
         run: |
           cargo install rustup-toolchain-install-master

cargo-miri/bin.rs

@@ -1,3 +1,5 @@
+mod version;
+
 use std::env;
 use std::ffi::{OsStr, OsString};
 use std::fmt::Write as _;
@@ -8,11 +10,10 @@
 use std::path::{Path, PathBuf};
 use std::process::{self, Command};
 
+use rustc_version::VersionMeta;
 use serde::{Deserialize, Serialize};
 
-use rustc_version::VersionMeta;
-
-const XARGO_MIN_VERSION: (u32, u32, u32) = (0, 3, 23);
+use version::*;
 
 const CARGO_MIRI_HELP: &str = r#"Runs binary crates and tests in Miri
 

cargo-miri/version.rs

@@ -0,0 +1,2 @@
+// We put this in a separate file so that it can be hashed for GHA caching.
+pub const XARGO_MIN_VERSION: (u32, u32, u32) = (0, 3, 26);