synapse_ynh corrupted form_secret and deleted itself during upgrade

[nykula]

Describe the bug

I tried upgrading from 1.77 to 1.79, the upgrade failed, automatic restoration of the pre-upgrade backup also failed, and I no longer see Synapse in the list of applications.

Moreover, form_secret in apps/synapse/backup/etc/matrix-synapse/homeserver.yaml from the pre-upgrade backup seems corrupted, with __FORM_SECRET__ appearing in place of every & in the secret. I think this command from the log was responsible for this:

sed --in-place 's@__FORM_SECRET__@...something_containing_&_characters...@g' /etc/matrix-synapse/homeserver.yaml

Context

• Hardware: dedicated x86-64 server
• YunoHost version: 11.1.6
• I have access to my server: through the webadmin
• Are you in a special context or did you perform some particular tweaking on your YunoHost instance?: maybe
  • If yes, please explain: I have Akkoma on the main domain, and Synapse on a subdomain. Synapse was installed first. It was configured through the webadmin to use the main domain in user names, so that the users have user@example.org mail, @user:example.org chats and @user@example.org social identifiers.
• Using, or trying to install package version/branch: 1.79
• If upgrading, current package version: was 1.77, but now there's none at all

Steps to reproduce

I went to the updates page in the YunoHost web UI, let it update applications including Synapse, and got an error.

Logs

I tried the automatic YunoPaste, but I see multiple leaks of macaroon_secret_key and form_secret and registration_shared_secret in the log so I won't publicly post the original paste.yunohost.org link, only a copy where I manually replace my values with <REDACTED>: https://paste.yunohost.org/raw/ivayobipux

[nykula]

I recovered Synapse by completely removing Akkoma, removing leftover permissions from failed Synapse backup restoration, and restoring the Synapse backup again.

However, the issue with corruption of secrets with & during backup/restore remains.

[Josue-T]

Closing as it should be fixed now with last release.