From 5e729eced7bfe40e84a0f5a3b82900c4dbf1f3a3 Mon Sep 17 00:00:00 2001
From: Martin von Zweigbergk <martinvonz@google.com>
Date: Tue, 19 Apr 2022 15:39:19 -0700
Subject: [PATCH] github: also run tests on our MSRV (1.58)

This patch sets up an additional CI strategy running tests on 1.58, to
make sure we don't accidentally use newer features. I've only made it
run on one platform (Linux) to avoid wasting resources. There's of
course a small risk that we start depending on platform-specific APIs
from newer versions.
---
 .github/workflows/build.yml | 22 ++++++++++++++++++----
 Cargo.toml                  |  2 +-
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b5279f422..730ca70ac 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -10,17 +10,31 @@ permissions: read-all
 
 jobs:
   build:
-    runs-on: ${{ matrix.operating-system }}
     strategy:
+      fail-fast: false
       matrix:
-        operating-system: [ ubuntu-latest, windows-latest, macos-latest ]
+        build: [linux, linux-msrv, macos, win]
+        include:
+        - build: linux
+          os: ubuntu-latest
+          rust_version: stable
+        - build: linux-msrv
+          os: ubuntu-latest
+          rust_version: 1.58
+        - build: macos
+          os: macos-latest
+          rust_version: stable
+        - build: win
+          os: windows-latest
+          rust_version: stable
+    runs-on: ${{ matrix.os }}
 
     steps:
     - uses: actions/checkout@dcd71f646680f2efd8db4afa5ad64fdcba30e748
-    - name: Install Rust (stable)
+    - name: Install Rust (${{ matrix.rust_version }})
       uses: actions-rs/toolchain@16499b5e05bf2e26879000db0c1d13f7e13fa3af
       with:
-        toolchain: stable
+        toolchain:  ${{ matrix.rust_version }}
         override: true
         profile: minimal
     - name: Build
diff --git a/Cargo.toml b/Cargo.toml
index c2992d649..ea6a2015a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ name = "jujutsu"
 version = "0.4.0"
 authors = ["Martin von Zweigbergk <martinvonz@google.com>"]
 edition = "2021"
-rust-version = "1.58"
+rust-version = "1.58"  # Remember to update CI
 license = "Apache-2.0"
 description = "Jujutsu (an experimental VCS)"
 homepage = "https://github.com/martinvonz/jj"