moshushi moshushi - 1 month ago 28
Python Question

Django Sass Compressor django_libsass.SassCompiler: command not found

I'm using a Django-Compressor Filter as part of Wagtail (Django variant CMS with super cool UI). Environment is Wagtail 0.2 + Python 2.7 + Django 1.6 + Virtualenv + FastCGI + Apache shared hosting.

Issue occurs when trying to access admin/login page of the CMS. Django shows an Error rendering template

Error during template rendering

In template /home/username/env/lib/python2.7/site-packages/wagtail/wagtailadmin/templates/wagtailadmin/skeleton.html, error at line 20
/bin/sh: django_libsass.SassCompiler: command not found


Line 20 of the skeleton.html is:

<!doctype html>
{% load compress %}
<!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7" lang="{{ LANGUAGE_CODE|default:"en-gb" }}"> <![endif]-->
<!--[if IE 7]> <html class="no-js lt-ie9 lt-ie8" lang="{{ LANGUAGE_CODE|default:"en-gb" }}"> <![endif]-->
<!--[if IE 8]> <html class="no-js lt-ie9" lang="{{ LANGUAGE_CODE|default:"en-gb" }}"> <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="{{ LANGUAGE_CODE|default:"en-gb" }}"> <!--<![endif]-->
<title>Wagtail - {% block titletag %}{% endblock %}</title>
<meta name="description" content="" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />

<script src="//cdnjs.cloudflare.com/ajax/libs/modernizr/2.6.2/modernizr.min.js"></script>

{% block css %}{# Block defined for timing breakdowns in django debug toolbar - not expected to be overridden #}
<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Open+Sans:300,400,600,700" />
<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Bitter:400,700" />
19
20 {% compress css %}
21 <link rel="stylesheet" href="{{ STATIC_URL }}wagtailadmin/scss/normalize.css" />
<link rel="stylesheet" href="{{ STATIC_URL }}wagtailadmin/scss/vendor/jquery-ui/jquery-ui-1.10.3.verdant.css" />
<link rel="stylesheet" href="{{ STATIC_URL }}wagtailadmin/scss/vendor/jquery.timepicker.css" />
<link rel="stylesheet" href="{{ STATIC_URL }}wagtailadmin/scss/core.scss" type="text/x-scss" />
{% endcompress %}

{% block extra_css %}{% endblock %}
{% endblock %}
</head>
<body class="{% block bodyclass %}{% endblock %} {% if messages %}has-messages{% endif %}">


the precompiler in my settings.py, DEBUG is set to True:

COMPRESS_ENABLED = True

COMPRESS_PRECOMPILERS = (
('text/x-scss', 'django_libsass.SassCompiler'),
)


TRIAL AND ERROR #1

I've tried changing to:

('text/x-scss', '/home/username/env/lib/python2.7/site-packages/django_libsass {infile} {outfile}')


but that leads me to a dictionary update sequence element #0 error.

I have django_libsass & compressor installed, also tried
pip install libsass
,
ngm install lessc
,
pip install sass
, turning
DEBUG = False
, adding
COMPRESSOR_OFFLINE
, adding
COMPRESSOR_ENABLED
as suggested in other similar questions. Running
manage.py compress
returns the same error.

Have rechecked and site-packages and django_libsass are indeed on my sys.path

SassCompiler can be found in
~/env/lib/python2.7/site-packages/django_libsass.py


TRIAL AND ERROR #2

Re-checked that
sass
is installed and on my path.

Change code to:

COMPRESS_PRECOMPILERS = (
('text/x-scss', 'sass --scss {infile} {outfile}'),
)


Returns error:

Exception Type: FilterError
Exception Value:
/bin/sh: sass: command not found


TRIAL AND ERROR #3

After reading this feedly issue, tried
pip install compass
to no effect

TRIAL AND ERROR #4

Following gasman's comment, I ran python manage.py shell and tried to import SassCompiler It works with no errors.

Python 2.7.6 (default, Nov 11 2013, 18:34:29)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from django_libsass import SassCompiler
>>>


Full Traceback

I do apologize if this question is getting too long.

Traceback:
File "/home/username/env/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
139. response = response.render()
File "/home/username/env/lib/python2.7/site-packages/django/template/response.py" in render
105. self.content = self.rendered_content
File "/home/username/env/lib/python2.7/site-packages/django/template/response.py" in rendered_content
82. content = template.render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/base.py" in render
140. return self._render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/base.py" in _render
134. return self.nodelist.render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/base.py" in render
840. bit = self.render_node(node, context)
File "/home/username/env/lib/python2.7/site-packages/django/template/debug.py" in render_node
78. return node.render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/loader_tags.py" in render
123. return compiled_parent._render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/base.py" in _render
134. return self.nodelist.render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/base.py" in render
840. bit = self.render_node(node, context)
File "/home/username/env/lib/python2.7/site-packages/django/template/debug.py" in render_node
78. return node.render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/loader_tags.py" in render
62. result = block.nodelist.render(context)
File "/home/username/env/lib/python2.7/site-packages/django/template/base.py" in render
840. bit = self.render_node(node, context)
File "/home/username/env/lib/python2.7/site-packages/django/template/debug.py" in render_node
78. return node.render(context)
File "/home/username/env/lib/python2.7/site-packages/compressor/templatetags/compress.py" in render
147. return self.render_compressed(context, self.kind, self.mode, forced=forced)
File "/home/username/env/lib/python2.7/site-packages/compressor/templatetags/compress.py" in render_compressed
107. rendered_output = self.render_output(compressor, mode, forced=forced)
File "/home/username/env/lib/python2.7/site-packages/compressor/templatetags/compress.py" in render_output
119. return compressor.output(mode, forced=forced)
File "/home/username/env/lib/python2.7/site-packages/compressor/css.py" in output
51. ret.append(subnode.output(*args, **kwargs))
File "/home/username/env/lib/python2.7/site-packages/compressor/css.py" in output
53. return super(CssCompressor, self).output(*args, **kwargs)
File "/home/username/env/lib/python2.7/site-packages/compressor/base.py" in output
246. content = self.filter_input(forced)
File "/home/username/env/lib/python2.7/site-packages/compressor/base.py" in filter_input
194. for hunk in self.hunks(forced):
File "/home/username/env/lib/python2.7/site-packages/compressor/base.py" in hunks
169. precompiled, value = self.precompile(value, **options)
File "/home/username/env/lib/python2.7/site-packages/compressor/base.py" in precompile
226. **kwargs)
File "/home/username/env/lib/python2.7/site-packages/django_libsass.py" in input
51. return compile(filename=self.filename)
File "/home/username/env/lib/python2.7/site-packages/django_libsass.py" in compile
41. return sass.compile(**kwargs)

Exception Type: AttributeError at /admin/login/
Exception Value: 'module' object has no attribute 'compile'

Answer

(Reposting my comments as an answer, as requested...)

The original error: django_libsass.SassCompiler: command not found

meant that it was failing to import the django-libsass library. (django-compressor responded to that failure by trying to treat it as a shell command instead - django_libsass is not a runnable command, so this failed too, giving the actual error seen here.) The solution is to ensure that django-libsass is installed - it should show up in the output of pip freeze.

The second error: 'module' object has no attribute 'compile'

meant that there was another package installed which defined a module called sass, and this was being loaded in place of the one we wanted, from the libsass package. The solution is to uninstall all sass-related packages apart from django-libsass and libsass.