我在Heroku上运行Elixir伞应用程序。一切都很好，但有一点。我正在使用:erlport, github: "hdima/erlport"来运行一些Ruby代码（asciidoctor-latex）。这适用于本地但不适用于Heroku。 （Heroku不能帮助我，因为他们不支持Elixir。）
我已将问题缩小到一行。有问题的应用是http://notefile.herokuapp.com（https://github.com/jxxcarlson/ns_umbrella），代码行位于app/apps/ruby_bridge/priv/ruby/asciidoc.rb：
# require 'asciidoctor-latex'
require "/app/vendor/bundle/ruby/2.3.0/bundler/gems/asciidoctor-latex-
b5c9de1363de/bin/asciidoctor-latex"
注释掉的行在本地工作但不在Heroku上工作。另一行是我向require提供绝对路径asciidoctor-latex的（失败）实验之一。
我知道这条线路是犯罪方，原因如下。首先，注释掉所有require行;然后，在asciidoc.rb中，使用result = "Text length = #{text.length}"代替result = Asciidoctor.convert text, { 'dialect' => 'latex' }
这里我已经用泛型Ruby代码替换了对asciidoctor-latex方法的调用。通过这些更改，应用程序不会崩溃并提供预期的输出。
结论：require无法找到目标。下面我列出了使用的构建包（按顺序）：
heroku/ruby
https://github.com/HashNuke/heroku-buildpack-elixir.git
https://github.com/gjaldon/heroku-buildpack-phoenix-static
日志：
Rendering ...
2017-05-02T18:52:00.071102+00:00 app[web.1]: ========================
2017-05-02T18:52:00.071023+00:00 app[web.1]: MU.RenderText in APPLICATION MU_SERVER
2017-05-02T18:52:00.071326+00:00 app[web.1]: %{mode: "show", note_id: 1065, process: :adoc_latex, public: false, user_id: 9,
2017-05-02T18:52:00.071181+00:00 app[web.1]: OPTIONS
2017-05-02T18:52:00.071327+00:00 app[web.1]: username: "jxxcarlson"}
2017-05-02T18:52:00.071392+00:00 app[web.1]: --
2017-05-02T18:52:00.071513+00:00 app[web.1]: Rendering asciidoc-latex
2017-05-02T18:52:00.150754+00:00 app[web.1]: Hello! This is render_asciidoc
2017-05-02T18:52:00.458499+00:00 heroku[router]: at=info method=GET path="/notes/1065" host=notefile.herokuapp.com request_id=f1ce45ba-6800-4d84-9b93-47851c0502e9 fwd="65.24.227.211" dyno=web.1 connect=0ms service=417ms status=500 bytes=243 protocol=https
2017-05-02T18:52:00.371673+00:00 app[web.1]: (1) Hello, I am here, in asciidoc.rb, top of file
2017-05-02T18:52:00.378538+00:00 app[web.1]: Starting MU.Server ...
2017-05-02T18:52:00.459594+00:00 app[web.1]: 18:52:00.459 [error] GenServer MUServer terminating
2017-05-02T18:52:00.459607+00:00 app[web.1]: ** (stop) {:ruby, :LoadError, "cannot load such file -- /app/vendor/bundle/ruby/2.3.0/bundler/gems/asciidoctor-latex-b5c9de1363de/bin/asciidoctor-latex", ["-e:1:in `<main>'", "/app/vendor/ruby-2.3.4/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'", "/app/vendor/ruby-2.3.4/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'", "/app/_build/prod/lib/erlport/priv/ruby1.9/erlport/cli.rb:94:in `<top (required)>'", "/app/_build/prod/lib/erlport/priv/ruby1.9/erlport/cli.rb:41:in `main'", "/app/_build/prod/lib/erlport/priv/ruby1.9/erlport/erlang.rb:138:in `start'", "/app/_build/prod/lib/erlport/priv/ruby1.9/erlport/erlang.rb:194:in `_receive'", "/app/_build/prod/lib/erlport/priv/ruby1.9/erlport/erlang.rb:234:in `call_with_error_handler'", "/app/_build/prod/lib/erlport/priv/ruby1.9/erlport/erlang.rb:195:in `block in _receive'", "/app/_build/prod/lib/erlport/priv/ruby1.9/erlport/erlang.rb:218:in `incoming_call'", "/app/vendor/ruby-2.3.4/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'", "/app/vendor/ruby-2.3.4/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'", "/app/apps/ruby_bridge/priv/ruby/asciidoc.rb:4:in `<top (required)>'", "/app/vendor/ruby-2.3.4/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'", "/app/vendor/ruby-2.3.4/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'"]}