I want to have a pipeline that needs to run at each merge request. I would also like to have the ability to run that pipeline manually so that one can anticipate merge issues.

However, if I specify my jobs as

```
only:
  - merge_requests

```

when trying to run the pipeline manually, I am greeted with a

> 
> Pipeline cannot be run. No stages / jobs for this pipeline.
> 
> 
> 

If I use workflows instead,

```
include:
  - template: 'Workflows/MergeRequest-Pipelines.gitlab-ci.yml'

```

I am greeted with a different but equivalent

> 
> Pipeline cannot be run. Pipeline filtered out by workflow rules.
> 
> 
> 

So how can I set up a pipeline that is required for merge requests but that could also be run manually by users on their feature branch?