comark/cast/read-failed · Point src at a file that can be read

The file exists but couldn't be read: it's a folder, the build may not read it, or a custom read option threw. The cast renders nothing, and the message ends with the error the reader gave.

Incorrect

::cast{src="ponds"}
::

lint-comark example.mdexample.md:1:1 comark/cast/read-failed::cast 1 "ponds": reading "ponds" failed: EISDIR: illegal operation on a directory, read.Check the file or the read option.✖ 1 problem

Correct

::cast{src="deploy.cast"}
::

lint-comark example.md✔ No problems