Eco error messages contain meaningless line numbers

error.html

<h2>Error reporting</h2>

<p>
    Does the error message for this page report the correct line number?
</p>

<% para = (phrase) -> %>
    <p><%= phrase %></p>
<% end %>

<%- para 'Hello world.' %>
<%- para 'What's up doc?' %>
<%- para 'Not much, how about you?' %>

<p>
    Good luck finding the error!
</p>

generated.coffee

_print _safe '<h2>Error reporting</h2>\n\n<p>\n    Does the error message for this page report the correct line number?\n</p>\n\n'
para = (phrase) ->
  _capture ->
    _print _safe '\n    <p>'
    _print phrase
    _print _safe '</p>\n'
_print _safe '\n\n'
_print _safe para 'Hello world.'
_print _safe '\n'
_print _safe para 'What's up doc?'
_print _safe '\n'
_print _safe para 'Not much, how about you?'
_print _safe '\n\n<p>\n    Good luck finding the error!\n</p>\n'