Error handling

[flying-sheep]

We probably want to switch to more concrete errors once the dust settles. Candidates:

• thiserror (if we want discernible structs)
• anyhow (if we just need user-displayable errors)

[getreu]

For a library like yours I would suggest thiserror.
From the web page:

Use thiserror if you care about designing your own dedicated error type(s) so that the caller receives exactly the information that you choose in the event of failure. This most often applies to library-like code. Use Anyhow if you don't care what error type your functions return, you just want it to be easy. This is common in application-like code.

[flying-sheep]

Yup, I think so too!

[oovm]

The Error needs re-export or I can't impl From from this error

[getreu]

Failure is officially deprecated/unmaintained

See output of cargo audit below.

Please consider migrating to an alternative, e.g. thiserror is widely used and maintained.

Crate:     failure
Version:   0.1.8
Warning:   unmaintained
Title:     failure is officially deprecated/unmaintained
Date:      2020-05-02
ID:        RUSTSEC-2020-0036
URL:       https://rustsec.org/advisories/RUSTSEC-2020-0036
Dependency tree:
failure 0.1.8
├── rst_renderer 0.4.0
│   └── tp-note 1.17.0
├── rst_parser 0.4.0
│   └── tp-note 1.17.0
└── document_tree 0.4.0
    ├── rst_renderer 0.4.0
    └── rst_parser 0.4.0