Add CI on 32bit Linux

(Stolen from the bytestring project)

Author: sjakobi

.github/workflows/32bit-ci.yml

@@ -0,0 +1,71 @@
+name: 32bit-ci
+on:
+  push:
+    branches:
+      - master
+  pull_request: {} # Validate all PRs
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: true
+      matrix:
+        os: [ubuntu-latest]
+        ghc: ['9.12']
+    steps:
+    - uses: actions/checkout@v4
+    - uses: haskell-actions/setup@v2
+      id: setup-haskell-cabal
+      with:
+        ghc-version: ${{ matrix.ghc }}
+    - name: Update cabal package database
+      run: cabal update
+    - uses: actions/cache@v3
+      name: Cache cabal stuff
+      with:
+        path: |
+          ${{ steps.setup-haskell-cabal.outputs.cabal-store }}
+          dist-newstyle
+        key: ${{ runner.os }}-${{ matrix.ghc }}
+    - name: Test
+      run: |
+        cabal sdist -z -o .
+        cabal get unordered-containers-*.tar.gz
+        cd unordered-containers-*/
+        cabal build unordered-containers:tests --enable-tests --enable-benchmarks
+        cabal test --enable-tests --enable-benchmarks --test-show-details=direct all
+    - name: Bench
+      run: |
+        cd unordered-containers-*/
+        cabal bench --enable-tests --enable-benchmarks --benchmark-option=-l all
+    - name: Haddock
+      run: |
+        cd unordered-containers-*/
+        cabal haddock all
+    - name: Cabal check
+      run: |
+        cd unordered-containers-*/
+        cabal check
+
+  i386:
+    needs: build
+    runs-on: ubuntu-latest
+    container:
+      image: i386/ubuntu:bionic
+    steps:
+    - name: Install
+      run: |
+        apt-get update -y
+        apt-get install -y autoconf build-essential zlib1g-dev libgmp-dev curl libncurses5 libtinfo5 libncurses5-dev libtinfo-dev
+        curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | BOOTSTRAP_HASKELL_NONINTERACTIVE=1 BOOTSTRAP_HASKELL_INSTALL_NO_STACK=1 sh
+    - uses: actions/checkout@v1 #This version must stay old enough to remain compatible with the container image
+    - name: Test
+      run: |
+        source ~/.ghcup/env
+        cabal update
+        cabal test