feature: generate macOS pkg files

.github/workflows/build-pkg.yml

@@ -0,0 +1,43 @@
+name: Build Homebrew package
+on:
+  push:
+    paths:
+      - .github/workflows/build-pkg.yml
+      - package/scripts
+  pull_request:
+    branches:
+      - master
+  release:
+    types:
+      - published
+
+jobs:
+  build:
+    runs-on: macos-12
+    env:
+      IDENTIFIER: sh.brew.Homebrew
+      TMP_PATH: /tmp/brew
+      MIN_OS: '11.0'
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          path: brew
+          fetch-depth: 0
+      - name: Version name
+        id: print-version
+        run: |
+          echo "version=$(git -C brew describe --tags --always)" > $GITHUB_OUTPUT
+      - name: Build package
+        run: |
+         pkgbuild --root brew \
+                  --scripts brew/package/scripts \
+                  --install-location "$TMP_PATH" \
+                  --identifier "$IDENTIFIER" \
+                  --min-os-version "$MIN_OS" \
+                  --filter .DS_Store \
+                  --version ${{ steps.print-version.outputs.version }} \
+                  Homebrew-${{ steps.print-version.outputs.version }}.pkg
+      - uses: actions/upload-artifact@v3
+        with:
+          name: Homebrew ${{ steps.print-version.outputs.version }}
+          path: Homebrew-${{ steps.print-version.outputs.version }}.pkg

.gitignore

@@ -179,6 +179,9 @@
 !/docs
 !/manpages
 
+# Unignore our packaging files
+!/package
+
 # Ignore generated documentation site
 /docs/_site
 /docs/bin

package/scripts/postinstall

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+# verify the files exist
+tmp_brew="$2"
+if [[ ! -d "${tmp_brew:?}" ]]; then
+    echo "no directory at $tmp_brew, exiting"
+    exit 1
+fi
+
+# pick the correct target
+if [[ "$3" != "/" ]]; then
+  target=$3
+elif [[ $(uname -m) == "x86_64" ]];then
+  target="/usr/local"
+else
+  target="/opt/Homebrew"
+fi
+
+loggedInUser=$(echo "show State:/Users/ConsoleUser" | scutil | awk '/Name :/ { print $3 }')
+if [[ -f "$target/bin/brew" ]]; then
+    if [[ $(sudo -u"$loggedInUser" "$target/bin/brew" developer) =~ "enabled" ]]; then
+      echo "developer install, exiting"
+      exit 0
+    fi
+    if [[ $("$tmp_brew/bin/brew" --version | head -n1) != $("$target/bin/brew" --version | head -n1) ]]; then
+      echo "already an outdated install at $target, updating"
+      sudo -u"$loggedInUser" "$target/bin/brew" update --auto-update
+    else
+      echo "already an up-to-date install at $target, exiting"
+    fi
+    exit 0
+fi
+
+group=$(id -gn "$loggedInUser")
+
+install -d -o "$loggedInUser" -g "$group" "$target"
+cp -RX "$tmp_brew/" "$target"
+
+# set permissions
+chown -R "$loggedInUser:$group" "$target/*"
+
+# cleanup
+rm -rf "${tmp_brew:?}/*"

package/scripts/preinstall

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# Checked for installed CLT
+if [[ -e "/Library/Developer/CommandLineTools/usr/bin/git" ]]; then
+  exit 0
+fi
+
+if /usr/bin/xcode-select --install; then
+  exit 0
+fi
+
+printf "Failed to install CommandLine Tools"
+exit 1