Looks like it:
Cloning into 'docker_manager'...
I, [2026-03-09T15:05:49.126710 #1] INFO -- : > cd /var/www/discourse/plugins && git clone https://github.com/discourse/discourse-cakeday.git
fatal: destination path 'discourse-cakeday' already exists and is not an empty directory.
FAILED
--------------------
Pups::ExecError: cd /var/www/discourse/plugins && git clone https://github.com/discourse/discourse-cakeday.git failed with return #<Process::Status: pid 146 exit 128>
Location of failure: /usr/local/lib/ruby/gems/3.3.0/gems/pups-1.4.0/lib/pups/exec_command.rb:138:in `spawn'
exec failed with the params {"cd"=>"$home/plugins", "cmd"=>["git clone https://github.com/discourse/docker_manager.git", "git clone https://github.com/discourse/discourse-cakeday.git", "git clone https://github.com/discourse/discourse-whos-online.git", "git clone -b no-regional-flags https://github.com/mentalstring/discourse-nationalflags.git", "git clone https://github.com/discourse/discourse-yearly-review.git", "git clone https://0fa273b19b56a1a58c41484d49a01d99f1b5b8d2@github.com/mentalstring/custom-username-validator", "git clone https://github.com/discourse/discourse-saved-searches"]}
bootstrap failed with exit code 128
---
HINT: The plugin 'discourse-cakeday' is now bundled with Discourse and should not be included in your container configuration.
Remove the line 'git clone https://github.com/discourse/discourse-cakeday' from your containers/web_only.yml file, then try again.
For more information, see https://meta.discourse.org/t/373574
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** FAILED TO BOOTSTRAP ** please scroll up and look for earlier error messages, there may be more than one.
Re-adding the plugin to app.yml causes the error above. Removing it immediately makes the build work again. This plugin seems to be the only issue.
I’m aware we are on a outdated version and it’s on the roadmap to upgrade. Just wanted to point out that, although we have not changed the version we are running, 3.5.4 went from building fine (with the plugin) to no longer building with the plugin and we don’t seem to have any way to get the plugin functionality back (through plugin or in core).