In #9434 a new component is introduced that includes the validator protoascii and the markdown describing how to use it. All component markdown files link to the validator protoascii for reference. However, check-links.js is showing an error because that link doesn't exist. While technically correct it would be false once the PR is merged.

Potential solutions:

• change check-links to emit a warning instead of an error
• if a deadlink is suspected and it is for a link to github.com/ampproject/amphtml/blob/master then check to see if the file exists within the PR

Here's the error

[03:46:11] Checking links in extensions/amp-imgur/amp-imgur.md ...
[03:46:11] [✖] https://github.com/ampproject/amphtml/blob/master/extensions/amp-imgur/0.1/validator-amp-imgur.protoascii
[03:46:11] ERROR Possible dead link(s) found in extensions/amp-imgur/amp-imgur.md (please update, or whitelist in build-system/tasks/check-links.js).
[03:46:11] ERROR Possible dead link(s) found. Please update, or whitelist in build-system/tasks/check-links.js. extensions/amp-imgur/amp-imgur.md

Note that extensions/amp-imgur/0.1/validator-amp-imgur.protoascii is a new file within PR #9434.