See if forcibly loading the correct libxml2 dylib before running the …

…tests fixes the lxml test failure on CI

setup/test.py

@@ -6,8 +6,7 @@
 import subprocess
 import sys
 
-from setup import Command
-
+from setup import Command, ismacos, is_ci
 TEST_MODULES = frozenset('srv db polish opf css docx cfi matcher icu smartypants build misc dbcli ebooks'.split())
 
 
@@ -41,6 +40,13 @@ def run(self, opts):
             self.info(f'Re-execing with LD_PRELOAD={os.environ["LD_PRELOAD"]}')
             sys.stdout.flush()
             os.execl('setup.py', *sys.argv)
+        if is_ci and ismacos:
+            import ctypes
+            sys.libxml2_dylib = ctypes.CDLL(os.path.join(os.environ['SW'], 'lib', 'libxml2.dylib'))
+            sys.libxslt_dylib = ctypes.CDLL(os.path.join(os.environ['SW'], 'lib', 'libxslt.dylib'))
+            sys.libexslt_dylib = ctypes.CDLL(os.path.join(os.environ['SW'], 'lib', 'libexslt.dylib'))
+            print(sys.libxml2_dylib, sys.libxslt_dylib, sys.libexslt_dylib, file=sys.stderr, flush=True)
+            del os.environ['DYLD_LIBRARY_PATH']
         from calibre.utils.run_tests import (
             filter_tests_by_name, remove_tests_by_name, run_cli, find_tests
         )

setup/unix-ci.py

@@ -161,6 +161,7 @@ def main():
         if ismacos:
             os.environ['SSL_CERT_FILE'] = os.path.abspath(
                 'resources/mozilla-ca-certs.pem')
+            os.environ['DYLD_LIBRARY_PATH'] = os.path.join(SW, 'lib')
 
         install_env()
         run_python('setup.py test')