Using windows, run:
wal-g.exe backup-push "C:/Program Files/PostgreSQL/13/data"
And the following error pops up:
ERROR: 2021/07/01 15:04:45.755930 !Data directory read from Postgres (C:Program FilesPostgreSQL13data) is different then as parsed (C:/Program Files/PostgreSQL/13/data).
Note that the difference is the forward/back slash.
Investigating the code, found that:
Note that it uses "ResolveSymlink" in just one side of comparison. Changing it to both sides solves the problem (since it will normalize inverted slashed in both paths.