Fix i686 Linux build failures.

mbedtls fails to build on 32-bit Linux without passing some compiler
options. We pass them through an environment variable, which is not the
best way to do it, but here we are.

Hopefully this will be able to be removed whenever mbedtls pushes a new
release; seems that this has been fixed upstream in merge
Mbed-TLS/mbedtls#8406.

pyproject.toml

@@ -94,6 +94,8 @@ skip = "cp36-*"
 # https:/johnnoone/pytest-curio/pull/7
 test-skip = "cp312*"
 
+build-verbosity = 1
+
 [tool.cibuildwheel.windows]
 # Windows builds fail because they try to use the same directory for different
 # architectures, and that's no good.

setup.py

@@ -1,8 +1,15 @@
 import os
 from subprocess import check_call
+import platform
 import shutil
 import sys
 
+if platform.machine() == "i686" and platform.system() == "Linux":
+ # mbedtls v3.5.1 will not build without these flags on 32-bit linux.
+ # https:/Mbed-TLS/mbedtls/issues/8334
+ # this is hopefully going to be fixed in another release.
+ # There is probably a better way to do this...
+ os.environ["CFLAGS"] = "-mpclmul -msse2 -maes"
 from setuptools import Command, setup, find_packages
 from setuptools.command.build_ext import build_ext
 from distutils.command.build import build as dbuild