docker/cli · error

cannot merge service %s: %w

Error message

cannot merge service %s: %w

What it means

Error "cannot merge service %s: %w" thrown in docker/cli.

Source

Thrown at cli/compose/loader/merge.go:82

			reflect.TypeFor[[]types.ServiceSecretConfig]():                   mergeSlice(toServiceSecretConfigsMap, toServiceSecretConfigsSlice),
			reflect.TypeFor[[]types.ServiceConfigObjConfig]():                mergeSlice(toServiceConfigObjConfigsMap, toSServiceConfigObjConfigsSlice),
			reflect.PointerTo(reflect.TypeFor[types.UlimitsConfig]()):        mergeUlimitsConfig,
			reflect.TypeFor[[]types.ServiceVolumeConfig]():                   mergeSlice(toServiceVolumeConfigsMap, toServiceVolumeConfigsSlice),
			reflect.TypeFor[types.ShellCommand]():                            mergeShellCommand,
			reflect.PointerTo(reflect.TypeFor[types.ServiceNetworkConfig]()): mergeServiceNetworkConfig,
			reflect.PointerTo(reflect.TypeFor[uint64]()):                     mergeUint64,
		}}),
	}

	baseServices := make(map[string]types.ServiceConfig, len(base))
	for _, s := range base {
		baseServices[s.Name] = s
	}

	for _, overrideService := range override {
		if baseService, ok := baseServices[overrideService.Name]; ok {
			if err := mergo.Merge(&baseService, &overrideService, mergeOpts...); err != nil {
				return nil, fmt.Errorf("cannot merge service %s: %w", overrideService.Name, err)
			}
			baseServices[overrideService.Name] = baseService
			continue
		}
		baseServices[overrideService.Name] = overrideService
	}

	services := make([]types.ServiceConfig, 0, len(baseServices))
	for _, baseService := range baseServices {
		services = append(services, baseService)
	}

	slices.SortFunc(services, func(a, b types.ServiceConfig) int {
		return cmp.Compare(a.Name, b.Name)
	})

	return services, nil
}

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/compose/loader/merge.go:82 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/5ba7f361b391290c.json. Report an issue: GitHub.