Hi Neutron Team, We are currently facing an issue in Tacker Zuul patch jobs build (with master branch), where the DevStack setup fails during the initial Neutron network creation step. Problem statement: The failure occurs at this point in the stack.sh script, for devstack environment creation in build process. Below command execution is failing in stack.sh [openstack --os-cloud devstack-admin-demo --os-region RegionOne router add subnet 20b264df-5f19-4599-a83d-2e76e7cbf5dc d777d04b-93ff-4e94-b6a9-cc8de3e23921] Error Message: This results in a 500 Internal Server Error, as seen in the logs: [HttpException: 500: Server Error for url: http://10.x.x.x/networking/v2.0/routers/20b264df-5f19-4599-a83d-2e76e7cbf5dc...] Analysis for the issue: Below error is coming in Neutron API logs: [ERROR neutron.plugins.ml2.ovo_rpc RuntimeError: cannot notify on un-acquired lock] 1. Tried overriding the required-projects in Zuul to use stable/2025.1 branches (instead of master) to identify project(master branch) which is causing root cause. 2. Tacker team has created DNM patch (952892) to invetsigate this in detail. https://review.opendev.org/c/openstack/tacker/+/952892 1. In DNM patch Patchset 11 (on June 29), we have taken devstack stable/2025.1. In stable branch the devstack environment created sucessfully. 2. In DNM patch Patchset 25 (on July 8), with the same devstack override (stable/2025.1), the job now fails earlier during DevStack setup. The logs show that Neutron failed to start, causing the job to fail across all nodes. As per observations and anlysis seems the recent changes in the Neutron master branch between June 29 and July 8 might be causing this issue. We’d appreciate your help in reviewing the changes in Neutron's master branch during that window that could cause this behavior and suggesting any debugging approaches or patches we can test on tacker. Please let us know if you'd like additional logs or info from the Zuul job runs. Thanks in advance for your support! Thanks & Regards, Renu Rani (レヌ ラニ) Mobile: +91-9311888962 E-mail: renu.rani@india.nec.com<mailto:renu.rani@india.nec.com> The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or NEC Corporation India Private Limited or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of NEC Corporation India Private Limited or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately.