virt-manager missing dependency

[agowa]

brew config AND brew doctor output OR brew gist-logs <formula> link

https://gist.github.com/agowa/1586687b296270196215ec06bb982466

Verification

• My brew doctor output says Your system is ready to brew. and am still able to reproduce my issue.
• I ran brew update and am still able to reproduce my issue.
• I have resolved all warnings from brew doctor and that did not fix my problem.
• I searched for recent similar issues at https://github.com/Homebrew/homebrew-core/issues?q=is%3Aissue and found no duplicates.
• My issue is not about a failure to build a formula from source.

What were you trying to do (and why)?

1. Install virt-manager (Initially I upgraded from an older version, but issue persisted after uninstalling and re-installing)
2. Try to connect to a remote over SSH.

What happened (include all command output)?

Unable to connect to libvirt qemu+ssh://user@PC-001.local/system.

No module named expat; use SimpleXMLTreeBuilder instead

Verify that an appropriate libvirt daemon is running on the remote host.

Libvirt URI is: qemu+ssh://user@PC-001.local/system

Traceback (most recent call last):
File "/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/xml/etree/ElementTree.py", line 1532, in init
from xml.parsers import expat
File "/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/xml/parsers/expat.py", line 4, in
from pyexpat import *
ImportError: dlopen(/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/lib-dynload/pyexpat.cpython-314-darwin.so, 0x0002): Symbol not found: _XML_SetAllocTrackerActivationThreshold
Referenced from: <1AAB1AFF-0B6A-3B67-86F5-A72CB69F8B1B> /opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/lib-dynload/pyexpat.cpython-314-darwin.so
Expected in: <4D62FA9D-D86A-3DD0-98F2-C6D0718849E8> /usr/lib/libexpat.1.dylib

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/xml/etree/ElementTree.py", line 1535, in init
import pyexpat as expat
ImportError: dlopen(/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/lib-dynload/pyexpat.cpython-314-darwin.so, 0x0002): Symbol not found: _XML_SetAllocTrackerActivationThreshold
Referenced from: <1AAB1AFF-0B6A-3B67-86F5-A72CB69F8B1B> /opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/lib-dynload/pyexpat.cpython-314-darwin.so
Expected in: <4D62FA9D-D86A-3DD0-98F2-C6D0718849E8> /usr/lib/libexpat.1.dylib

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtManager/connection.py", line 940, in _do_open
self._backend.open(cb, data)
~~~~~~~~~~~~~~~~~~^^^^^^^^^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/connection.py", line 184, in open
self._get_caps() # cache and log capabilities
~~~~~~~~~~~~~~^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/connection.py", line 109, in _get_caps
self._caps = Capabilities(self, capsxml)
~~~~~~~~~~~~^^^^^^^^^^^^^^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/capabilities.py", line 209, in init
XMLBuilder.init(self, *args, **kwargs)
~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/xmlbuilder.py", line 544, in init
self._xmlstate = _XMLState(self.XML_NAME, parsexml, parentxmlstate, relative_object_xpath)
~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/xmlbuilder.py", line 436, in init
self.parse(parsexml, parentxmlstate)
~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/xmlbuilder.py", line 453, in parse
self.xmlapi = XMLAPI(parsexml)
~~~~~~^^^^^^^^^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/xmletree.py", line 154, in init
node, namespaces = _fromstring(parsexml)
~~~~~~~~~~~^^^^^^^^^^
File "/opt/homebrew/Cellar/virt-manager/5.1.0_4/share/virt-manager/virtinst/xmletree.py", line 72, in _fromstring
parser = ET.XMLParser(target=builder)
File "/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/xml/etree/ElementTree.py", line 1537, in init
raise ImportError(
"No module named expat; use SimpleXMLTreeBuilder instead"
)
ImportError: No module named expat; use SimpleXMLTreeBuilder instead

What did you expect to happen?

virt-manager working as in former versions

Step-by-step reproduction instructions (by running brew commands)

1. brew install virt-manager

[cho-m]

macOS: 26.2-arm64
CLT: 26.3.0.0.1.1771626560
Xcode: 26.4

You will need to upgrade your macOS version as Apple has upgraded their system libexpat in macOS 26.3

• https://support.apple.com/en-us/126348

The upgrade is no longer compatible with older libexpat on macOS 26.0-26.2

[cho-m]

Closing as we consider not using latest minor/patch macOS version and Xcode CLT version a Tier 2 configuration.