Erpnext cannot activate developer mode

For some reason I just cannot activate the developer mode.
I have set the "developer_mode": 1 in bench/sites/library2/site_config.json and ran bench clear-cache to no avail. Also is there a way to disable the default site and app from being created when using bench init? Any suggestion about how to start debugging this problem? I’m following this getting started gude:

Did you try bench restart? The config file is only read at startup.

Bench (v5.2.1) init does not usually create a site. Frappe app is always created.

➜  ~ bench init test-bench
$ /usr/local/bin/virtualenv -q env -p python3
Already using interpreter /usr/bin/python3

Getting frappe
$ git clone  --depth 1 --origin upstream
Cloning into 'frappe'...
remote: Enumerating objects: 3008, done.
remote: Counting objects: 100% (3008/3008), done.
remote: Compressing objects: 100% (2813/2813), done.
remote: Total 3008 (delta 410), reused 1060 (delta 126), pack-reused 0
Receiving objects: 100% (3008/3008), 12.87 MiB | 9.09 MiB/s, done.
Resolving deltas: 100% (410/410), done.

Installing frappe
$ test-bench/env/bin/pip install -q -U -e test-bench/apps/frappe 
ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts.

We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default.

google-api-core 1.22.4 requires google-auth<2.0dev,>=1.21.1, but you'll have google-auth 1.18.0 which is incompatible.
$ yarn install
yarn install v1.22.4
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
warning " > bootstrap@4.4.1" has unmet peer dependency "jquery@1.9.1 - 3".
warning " > bootstrap@4.4.1" has unmet peer dependency "popper.js@^1.16.0".
[4/4] Building fresh packages...
warning Your current version of Yarn is out of date. The latest version is "1.22.5", while you're on "1.22.4".
info To upgrade, run the following command:
$ curl --compressed -o- -L | bash
$ yarn run snyk-protect
yarn run v1.22.4
$ snyk protect
Successfully applied Snyk patches

Done in 7.01s.
Done in 27.42s.
Updating node packages...

Installing node dependencies for frappe
$ yarn install
yarn install v1.22.4
[1/4] Resolving packages...
success Already up-to-date.
$ yarn run snyk-protect
yarn run v1.22.4
$ snyk protect
Successfully applied Snyk patches

Done in 4.43s.
Done in 5.49s.
$ bench build
Retreiving assets...

✔ Downloaded Frappe assets from

Extracting assets...

An Error occurred while downloading assets...
yarn run v1.22.4
$ FRAPPE_ENV=production node rollup/build.js
Production mode
✔ Built js/moment-bundle.min.js
✔ Built js/libs.min.js

Building frappe assets...

✔ Built js/checkout.min.js
✔ Built js/dialog.min.js
✔ Built js/social.min.js
✔ Built js/web_form.min.js
✔ Built js/list.min.js
✔ Built js/chat.js
✔ Built js/bootstrap-4-web.min.js
✔ Built js/frappe-recorder.min.js
✔ Built js/barcode_scanner.min.js
✔ Built js/frappe-web.min.js
✔ Built css/frappe-rtl.css
✔ Built js/report.min.js
✔ Built css/report.min.css
✔ Built css/list.min.css
✔ Built frappe/css/email.css
✔ Built css/frappe-chat-web.css
✔ Built css/form.min.css
✔ Built css/printview.css
✔ Built css/web_form.css
✔ Built css/desk.min.css
✔ Built js/data_import_tools.min.js
✔ Built css/frappe-web-b4.css
✔ Built js/control.min.js
✔ Built js/form.min.js
✔ Built js/desk.min.js
✨  Done in 66.646s
Done in 68.41s.
SUCCESS: Bench test-bench initialized
You have new mail.                                                                                                                                                                  
➜  ~ ls test-bench/sites/
apps.txt  assets  common_site_config.json
➜  ~ ls test-bench/apps 

Tried bench restart and closing and restarting the server by hand, no change. Also it prompted me to create a user the first time I connected through a browser. Is this normal or is it running some other site/application altogether than the one I just created?

I’m running the following commands to reproduce this:

bench init test-bench && cd test-bench
bench start &
bench new-site library
bench new-app library_management
bench --site library install-app library_management
bench set-config developer_mode 1
bench clear-cache
bench restart

No development link in the ui.