Add steps to build with custom toolchains

.github/workflows/prerelease.yml

@@ -89,9 +89,82 @@
         name: python-wheels-${{ matrix.os }}-${{ matrix.python-version }}
         path: ./bazel-bin/*.whl
 
+  build_wheels_for_legacy_systems:
+    runs-on: ${{ matrix.os }}
+    needs: [create_version]
+    strategy:
+      fail-fast: true
+      matrix:
+        os: [ubuntu-22.04]
+        python-version: ['3.10', '3.11', '3.12', '3.13']
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v4
+    - name: Set up Python
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v5
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7.0.0
+      with:
+        name: version-file
+        path: version
+
+
+    - name: Set Python Version
+      env:
+        TARGET_PYTHON: ${{ matrix.python-version }}
+      run: |
+        echo "set version to ${TARGET_PYTHON}"
+        python _update_bazel_py_version.py $TARGET_PYTHON
+
+    - name: build custom C++ toolchain
+      env:
+        TARGET_PYTHON: ${{ matrix.python-version }}
+      run: |
+        . devtools/build_with_custom_toolchain.sh
+
+
+    - name: Set up Bazel
+      uses: bazel-contrib/setup-bazel@083175551ceeceebc757ebee2127fde78840ca77 # 0.18.0
+      with:
+        bazelisk-cache: true
+        disk-cache: ${{ github.workflow }}
+        repository-cache: true
+
+
+    - name: Build package
+      env:
+        TARGET_PYTHON: ${{ matrix.python-version }}
+      run: |
+        export GLIBC_VERSION=2_28
+        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
+
+
+    - name: Test
+      run: |
+        pip install pytest sinter auditwheel
+
+        auditwheel show $(ls bazel-bin/*.whl)
+
+        pip install bazel-bin/*.whl
+
+        mv src/py/ src/_lib  # rename because `py` causes pytest issues.
+        rm src/_lib/stub_test.py  # ignore this test because it uses os flags that are set by bazel
+        rm src/_lib/tesseract_sinter_compat_test.py # ignore this test because it mixes np.int64 and int which doesn't work with older python versions
+
+        PYTHONPATH=src/_lib/::$PYTHONPATH pytest src/_lib/
+
+
+    - uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
+      with:
+        name: python-wheels-${{ matrix.os }}-${{ matrix.python-version }}-legacy
+        path: ./bazel-bin/*.whl
+
   release-wheels:
     name: Publish all wheels
-    needs: [build_wheels]
+    needs: [build_wheels,build_wheels_for_legacy_systems]
     runs-on: ubuntu-24.04
 
     steps:

MODULE.bazel

@@ -1,9 +1,9 @@
 module(name = "tesseract", version = "1.0")
 
-bazel_dep(name = "bazel_skylib", version = "1.7.1")
-bazel_dep(name = "platforms", version = "0.0.10")
-bazel_dep(name = "rules_python", version = "0.40.0")
-bazel_dep(name = "rules_cc", version = "0.0.17")
+bazel_dep(name = "bazel_skylib", version = "1.9.0")
+bazel_dep(name = "platforms", version = "1.0.0")
+bazel_dep(name = "rules_python", version = "1.9.0")
+bazel_dep(name = "rules_cc", version = "0.2.17")
 bazel_dep(name = "pybind11_bazel", version = "2.13.6")
 
 DEFAULT_PYTHON_VERSION = "3.13"
@@ -29,3 +29,76 @@ pip.parse(
 )
 
 use_repo(pip, "pypi")
+
+http_archive = use_repo_rule("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+git_repository = use_repo_rule("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+bazel_dep(name = "zlib", version = "1.3.2")
+
+HIGHS_VERSION = "1.9.0"
+HIGHS_SHA_256 = "dff575df08d88583c109702c7c5c75ff6e51611e6eacca8b5b3fdfba8ecc2cb4"
+
+git_repository(
+    name = "stim",
+    commit = "bd60b73525fd5a9b30839020eb7554ad369e4337",
+    remote = "https://github.com/quantumlib/stim.git",
+    shallow_since = "1741128853 +0000",
+)
+
+http_archive(
+    name = "highs",
+    sha256 = HIGHS_SHA_256,
+    build_file = "//external:highs.BUILD",
+    strip_prefix = "HiGHS-" + HIGHS_VERSION,
+    urls = ["https://github.com/ERGO-Code/HiGHS/archive/refs/tags/v" + HIGHS_VERSION + ".tar.gz"],
+)
+
+GTEST_VERSION = "1.13.0"
+
+GTEST_SHA256 = "ad7fdba11ea011c1d925b3289cf4af2c66a352e18d4c7264392fead75e919363"
+
+http_archive(
+    name = "gtest",
+    sha256 = GTEST_SHA256,
+    strip_prefix = "googletest-%s" % GTEST_VERSION,
+    urls = ["https://github.com/google/googletest/archive/refs/tags/v%s.tar.gz" % GTEST_VERSION],
+)
+
+ARGPARSE_SHA_256 = "3e5a59ab7688dcd1f918bc92051a10564113d4f36c3bbed3ef596c25e519a062"
+
+http_archive(
+    name = "argparse",
+    build_file = "//external:argparse.BUILD",
+    sha256 = ARGPARSE_SHA_256,
+    strip_prefix = "argparse-3.1",
+    urls = ["https://github.com/p-ranav/argparse/archive/refs/tags/v3.1.zip"],
+)
+
+git_repository(
+    name = "nlohmann_json",
+    commit = "9cca280a4d0ccf0c08f47a99aa71d1b0e52f8d03",
+    remote = "https://github.com/nlohmann/json.git",
+    shallow_since = "1701207391 +0100",
+)
+
+
+
+
+BOOST_VERSION = "1.83.0"
+BOOST_ARCHIVE_NAME = "boost_{}".format(BOOST_VERSION.replace(".", "_"))
+
+http_archive(
+    name = "boost",
+    urls = [
+        "https://archives.boost.io/release/{}/source/{}.tar.gz".format(
+            BOOST_VERSION,
+            BOOST_ARCHIVE_NAME,
+        )
+    ],
+    strip_prefix = BOOST_ARCHIVE_NAME,
+    sha256 = "c0685b68dd44cc46574cce86c4e17c0f611b15e195be9848dfd0769a0a207628",
+    build_file = "//external:boost.BUILD",
+)
+
+cc_compatibility_proxy = use_extension("@rules_cc//cc:extensions.bzl", "compatibility_proxy")
+use_repo(cc_compatibility_proxy, "cc_compatibility_proxy")
+

devtools/build_with_custom_toolchain.sh

@@ -0,0 +1,71 @@
+# 1. Start a temporary background container named 'sysroot-builder'
+docker run -d --name sysroot-builder debian:10 sleep 3600
+
+# 2. Run the installation and packaging process inside the container
+docker exec sysroot-builder bash -c "
+  sed 's/deb.debian.org/archive.debian.org/g' /etc/apt/sources.list  -i 
+
+  apt-get update && apt-get upgrade -y && apt-get install -y build-essential libc6-dev symlinks apt-utils
+
+  # 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
+
+  ldd --version
+
+  # 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
+ls -l -R custom_sysroot
+
+# create custom_sysroot/BUILD
+echo """filegroup(
+    name = \"sysroot\",
+    srcs = glob([\"**/*\"]),
+    visibility = [\"//visibility:public\"],
+)""" > custom_sysroot/BUILD
+
+# update MODULE.bazel to use the custom toolchain
+echo """bazel_dep(name = \"toolchains_llvm\", version = \"1.6.0\")
+
+llvm = use_extension(\"@toolchains_llvm//toolchain/extensions:llvm.bzl\", \"llvm\")
+llvm.toolchain(
+    name = \"llvm_toolchain\",
+    llvm_version = \"17.0.6\",
+)
+
+llvm.sysroot(
+    name = \"llvm_toolchain\",
+    label = \"//custom_sysroot:sysroot\",
+    targets = [\"linux-x86_64\"],
+)
+use_repo(llvm, \"llvm_toolchain\")
+
+register_toolchains(\"@llvm_toolchain//:all\")
+""" >> MODULE.bazel
+
+
+sudo apt-get update
+sudo apt-get install -y libxml2
+
+cd custom_sysroot/lib64/
+rm -f ld-linux-x86-64.so.2
+ln -s ../lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 ld-linux-x86-64.so.2
+cd ../..