Add steps to build with custom toolchains

Author: NoureldinYosri

.github/workflows/prerelease.yml

@@ -18,6 +18,7 @@ on:
   push:
     branches:
     - main
+  pull_request:
 
 permissions:
   contents: read
@@ -83,12 +84,17 @@ jobs:
         echo $GLIBC_VERSION
         sed "s/^MANYLINUX_VERSION.*/MANYLINUX_VERSION=\"manylinux_${GLIBC_VERSION}_x86_64.manylinux2014_x86_64\"/" BUILD -i || true
         bazel build --define GLIBC_VERSION=$GLIBC_VERSION --define TARGET_VERSION="$(python -c "print(\"py${TARGET_PYTHON}\".replace(\".\", \"\"))")" --define VERSION="$(cat version/version.txt)"  :tesseract_decoder_wheel
-
+      
     - uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
       with:
         name: python-wheels-${{ matrix.os }}-${{ matrix.python-version }}
         path: ./bazel-bin/*.whl
 
+    - name: Build with custom toolchain
+      env:
+        TARGET_PYTHON: ${{ matrix.python-version }}
+      run: ./devtools/build_with_custom_toolchain.sh
+
   release-wheels:
     name: Publish all wheels
     needs: [build_wheels]

devtools/build_with_custom_toolchain.sh

@@ -0,0 +1,32 @@
+# 1. Start a temporary background container named 'sysroot-builder'
+docker run -d --name sysroot-builder debian:11.11 sleep 3600
+
+# 2. Run the installation and packaging process inside the container
+docker exec sysroot-builder bash -c "
+  apt-get update && apt-get install -y build-essential libc6-dev symlinks
+  
+  # Convert absolute symlinks to relative (CRITICAL so Clang doesn't read your host OS files)
+  symlinks -rc /lib /usr/lib /usr/include
+  
+  # Create the staging directory
+  mkdir -p /sysroot/usr/lib /sysroot/usr/include /sysroot/lib /sysroot/lib64
+  
+  # Copy files while preserving symlinks (-a)
+  cp -a /usr/include/* /sysroot/usr/include/
+  cp -a /usr/lib/* /sysroot/usr/lib/
+  cp -a /lib/* /sysroot/lib/ 2>/dev/null || true
+  cp -a /lib64/* /sysroot/lib64/ 2>/dev/null || true
+  
+  # Create a tarball inside the container
+  cd /sysroot && tar -czf /sysroot.tar.gz .
+"
+
+# 3. Copy the tarball from the container directly to your host machine
+docker cp sysroot-builder:/sysroot.tar.gz ./sysroot.tar.gz
+
+# 4. Extract the contents into your project and clean up
+mkdir -p custom_sysroot
+tar -xzf sysroot.tar.gz -C custom_sysroot
+rm sysroot.tar.gz
+docker rm -f sysroot-builder
+