ci: split into two distinct jobs

The previous commit introduced two lists of ruby to use, but that meant that we
now had triples to test, exploding the amount of tests without reason.

In order to avoid this, split the build into a macOS-specific build and a
Ubuntu-specific one which avoids the branching though it does lead to some
duplicated code.

It does however still achieve the goal of not having to change the Ubuntu
build's ruby versions constantly which is still less overhead.

Author: carlosmn

.github/workflows/ci.yml

@@ -8,43 +8,57 @@ on:
     - maint/*
 
 jobs:
-  build:
+  macOS:
     strategy:
       fail-fast: false
       matrix:
-        ruby-mac: [ '2.4.9', '2.5.7', '2.6.5', '2.7.0' ]
-        ruby-linux: [ '2.4', '2.5', '2.6', '2.7' ]
-        os: [ ubuntu-18.04, macOS-latest ]
+        ruby: [ '2.4.9', '2.5.7', '2.6.5', '2.7.0' ]
+        os: [ macOS-latest ]
+    runs-on: ${{ matrix.os }}
 
+    name: Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@master
+    - name: update submodule
+      run: git submodule update --init
+    - name: Install macOS packages
+      run: ./vendor/libgit2/azure-pipelines/setup-osx.sh
+    - name: Set up Ruby on macOS
+      run: |
+        brew install rbenv
+        rbenv install ${{ matrix.ruby }}
+        rbenv local ${{ matrix.ruby }}
+    - name: run build
+      run: |
+        eval "$(rbenv init -)"
+        ruby --version
+        gem install bundler
+        bundle install --path vendor
+        ./script/travisbuild
+
+  ubuntu:
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby: [ '2.4', '2.5', '2.6', '2.7' ]
+        os: [ ubuntu-18.04 ]
     runs-on: ${{ matrix.os }}
 
-    name: Ruby ${{ matrix.ruby-mac }} ${{ matrix.ruby-linux }} on ${{ matrix.os }}
+    name: Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
     steps:
     - uses: actions/checkout@master
     - name: update submodule
       run: git submodule update --init
     - name: Install Linux packages
-      if: runner.os == 'Linux'
       run: |
         sudo apt update
         sudo apt install -y cmake libssh2-1-dev openssh-client openssh-server
-    - name: Install macOS packages
-      if: runner.os == 'macOS'
-      run: ./vendor/libgit2/azure-pipelines/setup-osx.sh
     - name: Set up Ruby on Linux
-      if: runner.os == 'Linux'
       uses: actions/setup-ruby@v1
       with:
-        ruby-version: ${{ matrix.ruby-linux }}
-    - name: Set up Ruby on macOS
-      if: runner.os == 'macOS'
-      run: |
-        brew install rbenv
-        rbenv install ${{ matrix.ruby-mac }}
-        rbenv local ${{ matrix.ruby-mac }}
+        ruby-version: ${{ matrix.ruby }}
     - name: run build
       run: |
-        if [ -x rbenv ]; then eval "$(rbenv init -)"; fi
         ruby --version
         gem install bundler
         bundle install --path vendor