Google: could not find default credentials

I check a backup of a remote machine to Google Cloud every month. The first step is listing the snapshots. Now that fails:

$ gpg -o/tmp/gs-secret-restic-key.json -d gs-secret-restic-key.json.gpg
$ GOOGLE_PROJECT_ID=wiwi-backup
$ GOOGLE_APPLICATION_CREDENTIALS=/tmp/gs-secret-restic-key.json
$ RESTIC_PASSWORD=`gpg -d repository_password.gpg`
$ R=gs:t550:/
$ restic -r $R snapshots

Did anyone else run into the issue and can give advice?

I have no idea what changed. I tried adding --verbose, but that didn’t result in additional information.

Please be more precise in regards to what happens when calling restic snapshots are there any errors, does it hang or whatever? Which restic version are you using? You could try setting the environment variable DEBUG_LOG=restic.log to get a debug log.

Sorry, forgot that. It returns immediately with an error message:

$ restic -r $R snapshots
Fatal: unable to open repository at gs:t550:/: getStorageClient: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information
$ restic version
restic 0.17.0 compiled with go1.23rc2 on linux/amd64

That version or an older version has worked fine in the past for listing the snapshots of that repository. I do it every month.

I don’t get a log file:

$ DEBUG_LOG=restic.log
$ restic -r $R snapshots
Fatal: unable to open repository at gs:t550:/: getStorageClient: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information
$ ls -a
.  ..

This either has to be

$ export DEBUG_LOG=restic.log
$ restic -r $R snapshots

or

$ DEBUG_LOG=restic.log restic -r $R snapshots

Are the credentials at that path still valid?