Clearer template errors should be given during build review
When putting a machine in build mode, if there is an error in the template the error message is very vague, like "Failure parsing <template name>: undefined method `<' for nil:NilClass.".
This makes debugging very hard. The error message should at least contain the line number for the line causing the error.
#6 Updated by Marek Hulán about 4 years ago
Error messages could be improved by using macros, that would have explicit checks on objects. There was a discussion on foreman-dev list recently that suggested using proxy objects on which we'd define such macros. The line number is technically possible only with safe mode disabled, #18432 adds this to the log at least.