invalid mount config for type "bind": field Source must not

Error message

invalid mount config for type "bind": field Source must not be empty

What it means

Error "invalid mount config for type "bind": field Source must not be empty" thrown in docker/cli.

Source

Thrown at cli/compose/loader/loader.go:493

			envVars = append(envVars, fileVars...)
		}
		updateEnvironment(environment,
			opts.ConvertKVStringsToMapWithNil(envVars), lookupEnv)
	}

	updateEnvironment(environment, serviceConfig.Environment, lookupEnv)
	serviceConfig.Environment = environment
	return nil
}

func resolveVolumePaths(volumes []types.ServiceVolumeConfig, workingDir string, lookupEnv template.Mapping) error {
	for i, volume := range volumes {
		if volume.Type != "bind" {
			continue
		}

		if volume.Source == "" {
			return errors.New(`invalid mount config for type "bind": field Source must not be empty`)
		}

		filePath := expandUser(volume.Source, lookupEnv)
		// Check if source is an absolute path (either Unix or Windows), to
		// handle a Windows client with a Unix daemon or vice-versa.
		//
		// Note that this is not required for Docker for Windows when specifying
		// a local Windows path, because Docker for Windows translates the Windows
		// path into a valid path within the VM.
		if !path.IsAbs(filePath) && !isAbs(filePath) {
			filePath = absPath(workingDir, filePath)
		}
		volume.Source = filePath
		volumes[i] = volume
	}
	return nil
}

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/compose/loader/loader.go:493 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/e32ee458a0dac2d8.json. Report an issue: GitHub.