WAL-E backups not working with modern swift versions

At some point between Icehouse and Stein (https://releases.openstack.org/teams/swift.html - quite a significant gap) something appears to have changed within Swift which is causing WAL-E to misinterpret the data being pulled from Swift.

Using Icehouse WAL-E is able to correctly backup to Swift, and list those backups.
Using Stein, WAL-E will make backups but can't correctly parse the output from swift when attempting to list backups.

This appears to be a known issue: https://github.com/wal-e/wal-e/issues/395 with an abandoned PR.

The root cause of this seems to be that swift used to include a leading slash when listing files inside a container, which is no longer the case.

Icehouse example:
$ swift list container | head -n1
/basebackups_005/base_0000000500000224000000EE_00000040/extended_version.txt

Stein example:
$ swift list container | head -n1
basebackups_005/base_000000020000003200000085_00000040/extended_version.txt

Given that WAL-E is now marked as obsolete (https://github.com/wal-e/wal-e#obsolescence-notice) perhaps we would be better served by migrating to WAL-G (https://github.com/wal-g/wal-g) than trying to fix this behaviour.