From 29a23851405f6fd74e4fdb1746063d7624364bdb Mon Sep 17 00:00:00 2001
From: Jonas Bushart <jonas@bushart.org>
Date: Tue, 19 Jul 2022 19:00:36 +0000
Subject: [PATCH] Better and more verbose version printing and cachekey
 version.

---
 CHANGELOG.md |  2 ++
 action.yml   | 20 ++++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4962446..e4cdd30 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * Install rustup if not available in the CI environment. (Linux only)
     The code is taken from this issue: <https://github.com/dtolnay/rust-toolchain/pull/8>
+* Add rustc version output suitable as a cache key.
+    This is based on <https://github.com/dtolnay/rust-toolchain/pull/20> and <https://github.com/dtolnay/rust-toolchain/pull/17>.
 
 ## [1.0.1] - 2022-04-20
 
diff --git a/action.yml b/action.yml
index 608fccf..a816ecd 100644
--- a/action.yml
+++ b/action.yml
@@ -33,6 +33,9 @@ outputs:
   rustup-version:
     description: "Version as reported by `rustup --version`"
     value: ${{steps.versions.outputs.rustup-version}}
+  cachekey:
+    description: A short hash of the rustc version, appropriate for use as a cache key. "20220627a831"
+    value: ${{steps.versions.outputs.cachekey}}
 
 runs:
   using: composite
@@ -60,15 +63,20 @@ runs:
         rustup toolchain install ${{inputs.toolchain}}${{steps.flags.outputs.targets}}${{steps.flags.outputs.components}} --profile minimal${{steps.flags.outputs.downgrade}} --no-self-update
         rustup default ${{inputs.toolchain}}
       shell: bash
+
     - name: Print installed versions
       id: versions
       run: |
-        echo "::set-output name=rustc-version::$(rustc --version)"
-        rustc --version
-        echo "::set-output name=cargo-version::$(cargo --version)"
-        cargo --version
-        echo "::set-output name=rustup-version::$(rustup --version)"
-        rustup --version
+        echo "::set-output name=rustc-version::$(rustc +${{inputs.toolchain}} --version)"
+        rustc +${{inputs.toolchain}} --version --verbose
+        echo "::set-output name=cargo-version::$(cargo +${{inputs.toolchain}} --version)"
+        cargo +${{inputs.toolchain}} --version --verbose
+        echo "::set-output name=rustup-version::$(rustup +${{inputs.toolchain}} --version)"
+        rustup +${{inputs.toolchain}} --version
+
+        DATE=$(rustc +${{inputs.toolchain}} --version --verbose | sed -ne 's/^commit-date: \(20[0-9][0-9]\)-\([01][0-9]\)-\([0-3][0-9]\)$/\1\2\3/p')
+        HASH=$(rustc +${{inputs.toolchain}} --version --verbose | sed -ne 's/^commit-hash: //p')
+        echo "::set-output name=cachekey::$(echo $DATE$HASH | head -c12)"
       shell: bash
 
     - name: "Setup Rust Caching"