Gerrit requires plugins to be converted from HTML to Javascript. A first attempt was made with https://gerrit.wikimedia.org/r/c/operations/puppet/+/678646 but got reverted. We have since upgraded to Gerrit 3.3 and the gerrit-theme.js shipped by that reverted commit is still on the server and takes precedence over the gerrit-theme.html. So essentially the conversion is done.
I independently gave it a try this morning on my local machine with https://gerrit.wikimedia.org/r/c/operations/software/gerrit/+/756109 . In the web ui it showed:
Plugin install error: Unrecognized plugin path /static/gerrit-theme.html from /static/gerrit-theme.html
The file that fails to load comes from Puppet: modules/gerrit/files/homedir/review_site/static/gerrit-theme.html which I guess is an HTML plugin for which support is removed in 3.4 https://www.gerritcodereview.com/3.4.html#html-plugin-support-is-removed. @Paladox you told me about it, have you ever made a patch to migrate or do you have any guidance as to what needs to be done? :]
HTML plugins should be migrated to JavaScript plugins. This also implies Polymer 2 plugins wouldn’t work any more. See also this announcement for more details.
From the javascript console:
initResin TypeError: URL constructor: /static/gerrit-theme.html is not a valid URL. Na http://127.0.0.1:8080/elements/gr-app.js:1 _getPluginKeyFromUrl http://127.0.0.1:8080/elements/gr-app.js:317 _updatePluginState http://127.0.0.1:8080/elements/gr-app.js:317 _failToLoad http://127.0.0.1:8080/elements/gr-app.js:317 loadPlugins http://127.0.0.1:8080/elements/gr-app.js:317 loadPlugins http://127.0.0.1:8080/elements/gr-app.js:317 ... Plugin loaded separately: /static/gerrit-theme.html Runtime info Gerrit UI (PolyGerrit) Gerrit Server Version: f712a44 Plugin codemirror-editor installed. gr-app.js:317:14209 Plugin delete-project installed. gr-app.js:317:14209 Plugin lfs installed. gr-app.js:317:14209 Plugin reviewers installed. gr-app.js:317:14209 Plugin zuul installed.