extra '/' in gs path

[verytable]

I'm using wal-e to push wals to google storage. Configuration:

cat /etc/wal-e.d/env/WALE_GS_PREFIX
gs://w-temp/wals

Command:

WALE_LOG_DESTINATION=stderr envdir /etc/wal-e.d/env /usr/local/bin/wal-e wal-push pg_wal/00000001000000000000000F
wal_e.worker.upload INFO     MSG: begin archiving a file
        DETAIL: Uploading "pg_wal/00000001000000000000000F" to "gs://w-temp/wals/wal_005/00000001000000000000000F.lzo".
        STRUCTURED: time=2018-11-05T20:21:58.171324-00 pid=2513 action=push-wal key=gs://w-temp/wals/wal_005/00000001000000000000000F.lzo prefix=wals/ seg=00000001000000000000000F state=begin
wal_e.worker.upload INFO     MSG: completed archiving to a file
        DETAIL: Archiving to "gs://w-temp/wals/wal_005/00000001000000000000000F.lzo" complete at 115.356KiB/s.
        STRUCTURED: time=2018-11-05T20:21:59.027102-00 pid=2513 action=push-wal key=gs://w-temp/wals/wal_005/00000001000000000000000F.lzo prefix=wals/ rate=115.356 seg=00000001000000000000000F state=complete

As a result, all files are written but:

gsutil ls gs://w-temp//wals
gs://w-temp//wals/wal_005/
gsutil ls gs://w-temp/wals
CommandException: One or more URLs matched no objects.

Desired behavior:

1. To have wals in gs://w-temp/wals and not in gs://w-temp//wals which turn out to be different directories.
2. To have consistent Archiving to logs.

Is there a way to achieve the desired behavior?