Fails on local setup

[emrekuecuek]

When I try to build the website with jekyll serve, I came across with this issue:

Configuration file: /home/kucuk/Documents/Sample-Jekyll-Site/_config.yml Traceback (most recent call last): 24: from /usr/local/bin/jekyll:23:in <main>' 23: from /usr/local/bin/jekyll:23:in load' 22: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/exe/jekyll:15:in <top (required)>' 21: from /var/lib/gems/2.7.0/gems/mercenary-0.4.0/lib/mercenary.rb:21:in program' 20: from /var/lib/gems/2.7.0/gems/mercenary-0.4.0/lib/mercenary/program.rb:44:in go' 19: from /var/lib/gems/2.7.0/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:in execute' 18: from /var/lib/gems/2.7.0/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:in each' 17: from /var/lib/gems/2.7.0/gems/mercenary-0.4.0/lib/mercenary/command.rb:221:in block in execute' 16: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/commands/serve.rb:86:in block (2 levels) in init_with_program' 15: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/command.rb:91:in process_with_graceful_fail' 14: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/command.rb:91:in each' 13: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/command.rb:91:in block in process_with_graceful_fail' 12: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/commands/build.rb:30:in process' 11: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/commands/build.rb:30:in new' 10: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/site.rb:36:in initialize' 9: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/site.rb:131:in setup' 8: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/plugin_manager.rb:21:in conscientious_require' 7: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/plugin_manager.rb:87:in require_plugin_files' 6: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/plugin_manager.rb:87:in each' 5: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/plugin_manager.rb:89:in block in require_plugin_files' 4: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/external.rb:57:in require_with_graceful_fail' 3: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/external.rb:57:in each' 2: from /var/lib/gems/2.7.0/gems/jekyll-4.2.0/lib/jekyll/external.rb:60:in block in require_with_graceful_fail' 1: from /usr/lib/ruby/2.7.0/rubygems/core_ext/kernel_require.rb:92:in require' /usr/lib/ruby/2.7.0/rubygems/core_ext/kernel_require.rb:92:in `require': /home/kucuk/Documents/Sample-Jekyll-Site/_plugins/generate_categories.rb:50: else without rescue is useless (SyntaxError) ...L = "" if (BASEURL == nil) else BASEURL ... ^~~~

Is there a way to resolve this issue? It works just fine on Github Pages when I fork the repo, but I could not managed to work it on my local setup.