src/vs/workbench/services/configurationResolver/common/configurationResolverUtils.ts/applyDeprecatedVariableMessage
export function applyDeprecatedVariableMessage(schema: IJSONSchema) {
	schema.pattern = schema.pattern || '^(?!.*\\$\\{(env|config|command)\\.)';
	schema.patternErrorMessage = schema.patternErrorMessage ||
		nls.localize('deprecatedVariables', "'env.', 'config.' and 'command.' are deprecated, use 'env:', 'config:' and 'command:' instead.");
}