This is the documentation for 4.2.1 version, which is not the latest version. Consider upgrading to 4.3.0.

To properly set parameters, check global parameters doc.

Show line when fails: compileDebug

Put compileDebug: true when compiling the template (it is the default value). When an exception occurs, the error message will mention the original template filename and the line.

The templates are transformed in plain JavaScript before rendering can occur. Therefore, when an exception or an error occurs during rendering, the JavaScript line number is generally not meaningful: what is useful is the line number of the original template (and its filename). compileDebug: true generates extra lines in the generated JavaScript code to map with the original template filename and line number.

As it adds extra lines of debug code for each generated line, it should be disabled for production.

See where a specific text has been generated

Sometimes you need to know exactly where a specific text present in the output comes from. When rendering, put renderDebug to true to see the exact path followed in the templates.

It will log each mixin it goes through, even when finally proven empty, thus expect some verbosity.

renderDebug is a rendering parameter, but it only works when compileDebug was true when compiling.

Sample output (on English tutorial):

The phone
tuto_en_US.pug: 36
has a display with
tuto_en_US.pug: 8
a physical size of
tuto_en_US.pug: 8
tuto_en_US.pug: 8
inches and
tuto_en_US.pug: 10
a screen-to-body ratio of
tuto_en_US.pug: 10
tuto_en_US.pug: 10
tuto_en_US.pug: 45
tuto_en_US.pug: 47
tuto_en_US.pug: 48
along with a battery of
tuto_en_US.pug: 48
tuto_en_US.pug: 48
tuto_en_US.pug: 49
When debugging, use it along randomSeed so that the generated text remains the same at each run.

To have a more readable output, consider using css:

.rosaenlg-debug {
  display: block;
  font-size: xx-small;
  font-family: monospace;