use -E to promote warning messages to error msgs

[technicalguy]

Exit with a non-zero status code if Werrors occur.

e.g. to exit with non-zero failure status code when there are overfull lines/boxes:

latexrun -E "overfull" report.tex -o report.pdf

This supports the use-case of using continuous integration to check against overfull lines in latex projects.

(Currently this only allows promotion of warnings to error messages, but perhaps it should allow any message to be promoted to an error?)

[technicalguy]

I realised it might actually be nicer to allow a "error-" prefix to the existing -W argument, rather than to add an -E argument.

[Diti]

Any news on this?

[technicalguy]

Sorry, I completely forgot about this, I can't remember if I finished it or not!
latexrun is just a python script though, so you could use the version on this branch if you really want/need this feature.