Jinja2 inline comments
Jinja2 has no support for comments within a {{ ... }} statement. You can only use comments outside of such statements, and then only with {# .. #} or ## comment.
{# .. #}is only meant for disabling part of a template or adding comments outside of other Jinja2 syntax. You can't nest these.# statementis the equivalent of{% statement %}, if line statements are enabled and so configured.## commentonly works if line statements are enabled, at which point it regarded as a comment.
Generally, outside of Jinja statements, use comments in the target language instead; e.g. <!-- comment --> when generating XML, etc.