if (options.rebase && !options.explicitRebaseTo) {
implicitRebaseToWarning = 'You have set `rebase: true` without giving `rebaseTo` option, which, in this case, defaults to the current working directory. '
+ 'You are then warned this can lead to unexpected URL rebasing (aka here be dragons)! '
+ 'If you are OK with the clean-css output, then you can get rid of this warning by giving clean-css a `rebaseTo: process.cwd()` option.';