workflow: build chroot with apk.static

.github/workflows/ci-x86.yml

@@ -356,21 +356,22 @@ jobs:
     # Create an Alpine Linux 3.21.2 chroot environment for building
     - name: Create Build Environment
       run: |
-        mkdir alpine-root && cd alpine-root
-        curl -L https://dl-cdn.alpinelinux.org/v3.21/releases/x86_64/alpine-minirootfs-3.21.0-x86_64.tar.gz | \
-        sudo tar xzv
         curl -L https://dl-cdn.alpinelinux.org/v3.21/main/x86_64/apk-tools-static-2.14.6-r2.apk | \
-        sudo tar xzv sbin/apk.static
+        tar xzv sbin/apk.static
 
+        sudo mkdir -p alpine-root/etc/apk
+        echo "https://dl-cdn.alpinelinux.org/v3.21/main/" | \
+        sudo tee alpine-root/etc/apk/repositories
+        sudo sbin/apk.static -p alpine-root -U --initdb add \
+          alpine-base alpine-sdk bash cmake doxygen g++ libunwind-dev lz4-dev \
+          xz-dev zlib-dev
+
+        cd alpine-root
         sudo mount -o bind /dev/ dev
         sudo mount -t proc proc proc
         sudo mount -t sysfs sys sys
         sudo mount -o bind ${{ github.workspace }}/DynamoRIO root
 
-        sudo sbin/apk.static upgrade -U
-        sudo sbin/apk.static add \
-          alpine-sdk bash cmake doxygen zlib-dev lz4-dev libunwind-dev xz-dev
-
     - name: Run Suite
       working-directory: ${{ github.workspace }}
       run: |