[Bug] Basic sweeper would behavior wrong with value type dict

[clouds56]

🐛 Bug

Description

# python main.py -m +a={x:1},{x:2} +a={y:10},{y:20}

import hydra
@hydra.main(version_base="1.3", config_path=None, config_name=None)
def main(cfg) -> None:
    print(cfg)

if __name__ == "__main__":
    main()

would only run with

[2025-12-20 18:18:03,320][HYDRA] Launching 2 jobs locally
[2025-12-20 18:18:03,320][HYDRA]        #0 : +a={y:10}
{'a': {'y': 10}}
[2025-12-20 18:18:03,348][HYDRA]        #1 : +a={y:20}
{'a': {'y': 20}}

It should be run 4 jobs

[2025-12-20 18:18:03,320][HYDRA] Launching 4 jobs locally
[2025-12-20 18:18:03,320][HYDRA]        #0 : +a={x:1} +a={y:10}
{'a': {'x': 1, 'y': 10}}
[2025-12-20 18:18:03,348][HYDRA]        #1 : +a={x:1} +a={y:20}
{'a': {'x': 1, 'y': 20}}
[2025-12-20 18:18:03,373][HYDRA]        #2 : +a={x:2} +a={y:10}
{'a': {'x': 2, 'y': 10}}
[2025-12-20 18:18:03,399][HYDRA]        #3 : +a={x:2} +a={y:20}
{'a': {'x': 2, 'y': 20}}

Checklist

• I checked on the latest version of Hydra
• I created a minimal repro (See this for tips).

To reproduce

see above

Expected Behavior

Works the same way without -m

System information

• Hydra Version :
• Python version :
• Virtual environment type and version :
• Operating system :

Additional context

hydra/hydra/_internal/core_plugins/basic_sweeper.py

Line 111 in 1ac07c7

final_overrides = OrderedDict()

The basic_sweeper would only take last key into account.