Liquid Exception: uninitialized class variable @@usePage in Jekyll::JekyllRdf::Helper::RdfHelper in /_layouts/default.html
Traceback (most recent call last):
64: from …/.vendor/ruby/2.5.0/bin/jekyll:23:in `<main>'
63: from …/.vendor/ruby/2.5.0/bin/jekyll:23:in `load'
62: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/exe/jekyll:13:in `<top (required)>'
61: from …/.vendor/ruby/2.5.0/gems/mercenary-0.3.6/lib/mercenary.rb:19:in `program'
60: from …/.vendor/ruby/2.5.0/gems/mercenary-0.3.6/lib/mercenary/program.rb:42:in `go'
59: from …/.vendor/ruby/2.5.0/gems/mercenary-0.3.6/lib/mercenary/command.rb:220:in `execute'
58: from …/.vendor/ruby/2.5.0/gems/mercenary-0.3.6/lib/mercenary/command.rb:220:in `each'
57: from …/.vendor/ruby/2.5.0/gems/mercenary-0.3.6/lib/mercenary/command.rb:220:in `block in execute'
56: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/commands/build.rb:16:in `block (2 levels) in init_with_program'
55: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/commands/build.rb:34:in `process'
54: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/commands/build.rb:63:in `build'
53: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/command.rb:26:in `process_site'
52: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/site.rb:73:in `process'
51: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/site.rb:194:in `render'
50: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/site.rb:453:in `render_docs'
49: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/site.rb:453:in `each'
48: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/site.rb:454:in `block in render_docs'
47: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/site.rb:454:in `each'
46: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/site.rb:456:in `block (2 levels) in render_docs'
45: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/renderer.rb:62:in `run'
44: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/renderer.rb:85:in `render_document'
43: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/renderer.rb:155:in `place_in_layouts'
42: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/renderer.rb:188:in `render_layout'
41: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/renderer.rb:123:in `render_liquid'
40: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:26:in `render!'
39: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:47:in `measure_time'
38: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:27:in `block in render!'
37: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:40:in `measure_bytes'
36: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:28:in `block (2 levels) in render!'
35: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:220:in `render!'
34: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:207:in `render'
33: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:242:in `with_profiling'
32: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:208:in `block in render'
31: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/block_body.rb:91:in `render'
30: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/block_body.rb:102:in `render_node_to_output'
29: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/tags/include.rb:136:in `render'
28: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/context.rb:123:in `stack'
27: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/tags/include.rb:138:in `block in render'
26: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:26:in `render!'
25: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:47:in `measure_time'
24: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:27:in `block in render!'
23: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:40:in `measure_bytes'
22: from …/.vendor/ruby/2.5.0/gems/jekyll-3.5.1/lib/jekyll/liquid_renderer/file.rb:28:in `block (2 levels) in render!'
21: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:220:in `render!'
20: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:207:in `render'
19: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:242:in `with_profiling'
18: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/template.rb:208:in `block in render'
17: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/block_body.rb:82:in `render'
16: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/block_body.rb:102:in `render_node_to_output'
15: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/tags/if.rb:41:in `render'
14: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/context.rb:123:in `stack'
13: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/tags/if.rb:42:in `block in render'
12: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/tags/if.rb:42:in `each'
11: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/tags/if.rb:44:in `block (2 levels) in render'
10: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/block_body.rb:91:in `render'
9: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/block_body.rb:102:in `render_node_to_output'
8: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/tags/assign.rb:24:in `render'
7: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/variable.rb:82:in `render'
6: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/variable.rb:82:in `inject'
5: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/variable.rb:82:in `each'
4: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/variable.rb:84:in `block in render'
3: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/context.rb:86:in `invoke'
2: from …/.vendor/ruby/2.5.0/gems/liquid-4.0.1/lib/liquid/strainer.rb:56:in `invoke'
1: from …/.vendor/ruby/2.5.0/gems/jekyll-rdf-3.0.0/lib/jekyll/filters/rdf_sparql_query.rb:57:in `sparql_query'
…/.vendor/ruby/2.5.0/gems/jekyll-rdf-3.0.0/lib/jekyll/helper/rdf_general_helper.rb:85:in `prefixes': uninitialized class variable @@usePage in Jekyll::JekyllRdf::Helper::RdfHelper (NameError)
I get the following error you can see this here: https://travis-ci.org/SmartDataAnalytics/sda.tech/builds/445592004