CI: Add Alpine 32-bit configuration

.github/workflows/alpine_32bit/Dockerfile.ci

@@ -0,0 +1,30 @@
+FROM i386/alpine:3.18
+
+RUN apk add \
+    linux-headers gnu-libiconv-dev \
+    g++ make ccache cmake \
+    proj-dev proj proj-util \
+    curl-dev tiff-dev \
+    zlib-dev zstd-dev xz-dev snappy-dev \
+    libjpeg-turbo-dev libpng-dev openjpeg-dev libwebp-dev expat-dev libkml-dev \
+    py3-numpy-dev python3-dev py3-setuptools py3-numpy py3-pip swig \
+    poppler-dev postgresql-dev \
+    openexr-dev libheif-dev xerces-c-dev geos-dev cfitsio-dev \
+    netcdf-dev libaec-dev hdf5-dev freexl-dev \
+    lz4-dev blosc-dev libdeflate-dev brotli-dev uriparser-dev \
+    libarchive-dev \
+    kealib-dev libjxl-dev \
+    json-c-dev giflib-dev \
+    libspatialite-dev librasterlite2-dev \
+    mariadb-connector-c-dev \
+    pcre2-dev \
+    qhull-dev \
+    unixodbc-dev \
+    libpq-dev \
+    apache-arrow-dev \
+    py3-pyarrow \
+    libxml2-dev libxslt-dev \
+    podofo-dev
+
+COPY requirements.txt /tmp/
+RUN python3 -m pip install --break-system-packages -U -r /tmp/requirements.txt

.github/workflows/alpine_32bit/build.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+set -e
+
+cmake ${GDAL_SOURCE_DIR:=..} \
+  -DCMAKE_BUILD_TYPE=Debug \
+  -DUSE_CCACHE=ON \
+  -DCMAKE_INSTALL_PREFIX=/usr \
+  -DIconv_INCLUDE_DIR=/usr/include/gnu-libiconv \
+  -DIconv_LIBRARY=/usr/lib/libiconv.so \
+  -DCMAKE_C_FLAGS=-Werror -DCMAKE_CXX_FLAGS=-Werror -DWERROR_DEV_FLAG="-Werror=dev"
+make -j$(nproc)

.github/workflows/alpine_32bit/test.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+set -e
+
+. ../scripts/setdevenv.sh
+
+export PYTEST="python3 -m pytest -vv -p no:sugar --color=no"
+
+make quicktest
+
+PYTEST_SKIP=
+PYTEST_XFAIL="gcore/tiff_ovr.py gdrivers/gribmultidim.py gdrivers/mbtiles.py gdrivers/vrtwarp.py gdrivers/wcs.py utilities/test_gdalwarp.py pyscripts/test_gdal_pansharpen.py"
+
+# Fails with ERROR 1: OGDI DataSource Open Failed: Could not find the dynamic library "vrf"
+PYTEST_SKIP="ogr/ogr_ogdi.py $PYTEST_SKIP"
+
+# Stalls on it. Probably not enough memory
+PYTEST_SKIP="gdrivers/jp2openjpeg.py $PYTEST_SKIP"
+
+# Failures for the following tests. See https://github.com/OSGeo/gdal/runs/1425843044
+
+# depends on tiff_ovr.py that is going to be removed below
+(cd autotest && $PYTEST utilities/test_gdaladdo.py)
+PYTEST_SKIP="autotest/utilities/test_gdaladdo.py $PYTEST_SKIP"
+
+for i in $PYTEST_XFAIL ; do
+    (cd autotest && $PYTEST $i || echo "Ignoring failure")
+done
+
+(cd autotest && $PYTEST $(echo " $PYTEST_SKIP $PYTEST_XFAIL" | sed -r 's/[[:space:]]+/ --ignore=/g'))

.github/workflows/linux_build.yml

@@ -62,6 +62,12 @@ jobs:
             container: alpine
             build_script: build.sh
 
+          - name: Alpine, gcc 32-bit
+            id: alpine_32bit
+            container: alpine_32bit
+            build_script: build.sh
+            test_script: test.sh
+
           - name: Fedora Rawhide, clang++
             id: fedora_rawhide
             travis_branch: sanitize