我不熟悉Ruby语言，当我尝试使用asciidoctor转换为pdf文件时，它将报告以下错误，并且我发现该错误发生在asciidoctor数学库中：
有人知道如何解决此问题吗？谢谢
Traceback (most recent call last):
20: from /home/eric/.gem/ruby/2.5.0/bin/asciidoctor:23:in `<main>'
19: from /home/eric/.gem/ruby/2.5.0/bin/asciidoctor:23:in `load'
18: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/bin/asciidoctor:15:in `<top (required)>'
17: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/cli/invoker.rb:111:in `invoke!'
16: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/cli/invoker.rb:111:in `each'
15: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/cli/invoker.rb:128:in `block in invoke!'
14: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:183:in `convert_file'
13: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:183:in `open'
12: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:183:in `block in convert_file'
11: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/convert.rb:78:in `convert'
10: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/load.rb:83:in `load'
9: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/document.rb:555:in `parse'
8: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/document.rb:555:in `each'
7: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/document.rb:556:in `block in parse'
6: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-2.0.10/lib/asciidoctor/document.rb:556:in `[]'
5: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-mathematical-0.3.0/lib/asciidoctor-mathematical/extension.rb:40:in `process'
4: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-mathematical-0.3.0/lib/asciidoctor-mathematical/extension.rb:40:in `each'
3: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-mathematical-0.3.0/lib/asciidoctor-mathematical/extension.rb:41:in `block in process'
2: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-mathematical-0.3.0/lib/asciidoctor-mathematical/extension.rb:100:in `handle_prose_block'
1: from /home/eric/.gem/ruby/2.5.0/gems/asciidoctor-mathematical-0.3.0/lib/asciidoctor-mathematical/extension.rb:135:in `handle_inline_stem'
/home/eric/.gem/ruby/2.5.0/gems/asciidoctor-mathematical-0.3.0/lib/asciidoctor-mathematical/extension.rb:135:in `gsub!': asciidoctor: FAILED: Failed to load AsciiDoc document - can't modify frozen String (FrozenError)
135 text.gsub!(stem_rx) {
136 if (m = $~)[0].start_with? '\\'
137 next m[0][1..-1]
138 end
139
140 if (eq_data = m[2].rstrip).empty?
141 next
142 else
143 source_modified = true
144 end
145
146 eq_data.gsub! '\]', ']'
147 subs = m[1].nil_or_empty? ? (to_html ? [:specialcharacters] : []) : (node.resolve_pass_subs m[1])
148 eq_data = node.apply_subs eq_data, subs unless subs.empty?
149 img_target, img_width, img_height = make_equ_image eq_data, nil, true, mathematical, image_output_dir, image_target_dir, format, inline
150 if inline
151 %(pass:[<span class="steminline"> #{img_target} </span>])
152 else
153 %(image:#{img_target}[width=#{img_width},height=#{img_height}])
154 end
155 } if (text != nil) && (text.include? ':') && ((support_stem_prefix && (text.include? 'stem:')) || (text.include? 'latexmath:'))```