add support for building 32bit wheels (not currently working due to a…

… zlib integration problem in the wheel repair step)

Makefile

@@ -13,6 +13,7 @@ CYTHON3_WITH_COVERAGE=$(shell $(PYTHON3) -c 'import Cython.Coverage; import sys;
 MANYLINUX_LIBXML2_VERSION=2.9.3
 MANYLINUX_LIBXSLT_VERSION=1.1.29
 MANYLINUX_IMAGE_X86_64=quay.io/pypa/manylinux1_x86_64
+MANYLINUX_IMAGE_686=quay.io/pypa/manylinux1_i686
 
 .PHONY: all inplace rebuild-sdist sdist build require-cython wheel_manylinux wheel
 
@@ -39,14 +40,16 @@ require-cython:
 	@[ -n "$(PYTHON_WITH_CYTHON)" ] || { \
 	    echo "NOTE: missing Cython - please use this command to install it: $(PYTHON) -m pip install Cython"; false; }
 
-wheel_manylinux: dist/lxml-$(LXMLVERSION).tar.gz
+wheel_manylinux: wheel_manylinux64   # wheel_manylinux32
+
+wheel_manylinux32 wheel_manylinux64: dist/lxml-$(LXMLVERSION).tar.gz
 	time docker run --rm -t \
 		-v $(shell pwd):/io \
 		-e CFLAGS="-O3 -mtune=generic -pipe -fPIC" \
 		-e LDFLAGS="$(LDFLAGS)" \
 		-e LIBXML2_VERSION="$(MANYLINUX_LIBXML2_VERSION)" \
 		-e LIBXSLT_VERSION="$(MANYLINUX_LIBXSLT_VERSION)" \
-		$(MANYLINUX_IMAGE_X86_64) \
+		$(if $(patsubst %32,,$@),$(MANYLINUX_IMAGE_X86_64),$(MANYLINUX_IMAGE_686)) \
 		bash /io/tools/manylinux/build-wheels.sh /io/$<
 
 wheel: