How exactly do state files work?

[ergo70]

If I generate a INCREMENTAL state.json by simply > state.json, the resulting file cannot be re-read by --state state.json.

time=2024-01-22 17:49:08 name=tap_postgres level=CRITICAL message=Extra data: line 2 column 1 (char 1117)
Traceback (most recent call last):
File "/home/ergo/Devel/singer.io/venv-tap-postgres/bin/tap-postgres", line 8, in
sys.exit(main())
File "/home/ergo/Devel/singer.io/venv-tap-postgres/lib/python3.10/site-packages/tap_postgres/init.py", line 448, in main
raise exc
File "/home/ergo/Devel/singer.io/venv-tap-postgres/lib/python3.10/site-packages/tap_postgres/init.py", line 445, in main
main_impl()
File "/home/ergo/Devel/singer.io/venv-tap-postgres/lib/python3.10/site-packages/tap_postgres/init.py", line 393, in main_impl
args = parse_args(REQUIRED_CONFIG_KEYS)
File "/home/ergo/Devel/singer.io/venv-tap-postgres/lib/python3.10/site-packages/tap_postgres/init.py", line 373, in parse_args
args.state = utils.load_json(args.state)
File "/home/ergo/Devel/singer.io/venv-tap-postgres/lib/python3.10/site-packages/singer/utils.py", line 109, in load_json
return json.load(fil)
File "/usr/lib/python3.10/json/init.py", line 293, in load
return loads(fp.read(),
File "/usr/lib/python3.10/json/init.py", line 346, in loads
return _default_decoder.decode(s)
File "/usr/lib/python3.10/json/decoder.py", line 340, in decode
raise JSONDecodeError("Extra data", s, end)
json.decoder.JSONDecodeError: Extra data: line 2 column 1 (char 1117)

However, if I manually remove everything up to the final STATE line, it works. What am I doing wrong?

best regards,

Ernst-Georg