Git-based gem dependencies break with Warbler on JRuby 9.4.13.0

[tillsc]

Environment:

• JRuby: 9.4.13.0
• Rails: 7.1.x
• Warbler: latest from GitHub (used via GitHub reference in gemspec)
• Tomcat: 9 (on macOS, via Homebrew)

Description:
If the Gemfile contains any git-based gem dependency (e.g. gem 'foo', git: 'https://github.com/...), the generated WAR file fails to boot. The error occurs during Bundler setup at runtime inside the servlet container.

Expected behavior:
Applications with Git-based dependencies in the Gemfile should boot correctly when deployed as WAR.

Actual behavior:
Application fails during initialization with a Bundler error.

Stacktrace:

org.jruby.rack.RackInitializationException: undefined method `[]' for nil:NilClass
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:95:in `version'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:452:in `supports_fetching_unreachable_refs?'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:215:in `depth'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:440:in `full_clone?'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:428:in `depth_args'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:412:in `extra_clone_args'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:175:in `clone_needs_extra_fetch?'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:107:in `checkout'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:354:in `with_path'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:82:in `current_branch'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:257:in `current_branch'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:94:in `to_s'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:233:in `load_spec_files'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/path.rb:97:in `local_specs'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:198:in `specs'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/lazy_specification.rb:145:in `materialize_for_installation'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/lazy_specification.rb:134:in `materialized_for_installation'
	from org/jruby/RubyArray.java:2009:in `each'
	from org/jruby/RubyEnumerable.java:860:in `filter_map'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/gem_helpers.rb:73:in `select_best_local_platform_match'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/materialization.rb:27:in `specs'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/materialization.rb:18:in `complete?'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/spec_set.rb:236:in `block in materialize_dependencies'
	from org/jruby/RubyKernel.java:1725:in `loop'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/spec_set.rb:222:in `materialize_dependencies'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/spec_set.rb:110:in `materialize'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/definition.rb:640:in `materialize'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/definition.rb:232:in `specs'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/definition.rb:299:in `specs_for'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/runtime.rb:18:in `setup'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler.rb:167:in `setup'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/setup.rb:16:in `block in <main>'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/ui/shell.rb:173:in `with_level'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/ui/shell.rb:119:in `silence'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/setup.rb:16:in `<main>'
	from org/jruby/RubyKernel.java:1187:in `require'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:136:in `require'
	from /opt/homebrew/Cellar/tomcat@9/9.0.107/libexec/webapps/myapp/WEB-INF/config/boot.rb:3:in `<main>'
	from org/jruby/RubyKernel.java:1187:in `require'
	from uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:136:in `require'
	from uri:classloader:/jruby/rack/rails/environment3.rb:23:in `load_environment'
	from uri:classloader:/jruby/rack/rails_booter.rb:83:in `load_environment'
	from <script>:1:in `<main>'

	at org.jruby.rack.RackInitializationException.wrap(RackInitializationException.java:30)
	at org.jruby.rack.RackApplicationFactoryDecorator.init(RackApplicationFactoryDecorator.java:107)
	at org.jruby.rack.RackServletContextListener.contextInitialized(RackServletContextListener.java:50)
	at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4059)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4501)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:164)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:599)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:571)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:603)
	at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1013)
	at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1861)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:545)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:328)
	at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:76)
	at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:124)
	at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:817)
	at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:468)
	at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1628)
	at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:308)
	at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:109)
	at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:973)
	at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1172)
	at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1176)
	at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1154)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:545)
	at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:369)
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:310)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1095)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:619)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63)
	at java.base/java.lang.Thread.run(Thread.java:1447)
Caused by: org.jruby.exceptions.NoMethodError: (NoMethodError) undefined method `[]' for nil:NilClass
	at RUBY.version(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:95)
	at RUBY.supports_fetching_unreachable_refs?(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:452)
	at RUBY.depth(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:215)
	at RUBY.full_clone?(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:440)
	at RUBY.depth_args(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:428)
	at RUBY.extra_clone_args(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:412)
	at RUBY.clone_needs_extra_fetch?(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:175)
	at RUBY.checkout(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:107)
	at RUBY.with_path(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:354)
	at RUBY.current_branch(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git/git_proxy.rb:82)
	at RUBY.current_branch(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:257)
	at RUBY.to_s(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:94)
	at RUBY.load_spec_files(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:233)
	at RUBY.local_specs(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/path.rb:97)
	at RUBY.specs(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/source/git.rb:198)
	at RUBY.materialize_for_installation(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/lazy_specification.rb:145)
	at RUBY.materialized_for_installation(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/lazy_specification.rb:134)
	at org.jruby.RubyArray.each(org/jruby/RubyArray.java:2009)
	at org.jruby.RubyEnumerable.filter_map(org/jruby/RubyEnumerable.java:860)
	at RUBY.select_best_local_platform_match(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/gem_helpers.rb:73)
	at RUBY.specs(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/materialization.rb:27)
	at RUBY.complete?(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/materialization.rb:18)
	at RUBY.materialize_dependencies(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/spec_set.rb:236)
	at org.jruby.RubyKernel.loop(org/jruby/RubyKernel.java:1725)
	at RUBY.materialize_dependencies(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/spec_set.rb:222)
	at RUBY.materialize(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/spec_set.rb:110)
	at RUBY.materialize(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/definition.rb:640)
	at RUBY.specs(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/definition.rb:232)
	at RUBY.specs_for(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/definition.rb:299)
	at RUBY.setup(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/runtime.rb:18)
	at RUBY.setup(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler.rb:167)
	at RUBY.<main>(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/setup.rb:16)
	at RUBY.with_level(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/ui/shell.rb:173)
	at RUBY.silence(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/ui/shell.rb:119)
	at RUBY.<main>(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/bundler/setup.rb:16)
	at org.jruby.RubyKernel.require(org/jruby/RubyKernel.java:1187)
	at RUBY.require(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:136)
	at RUBY.<main>(/opt/homebrew/Cellar/tomcat@9/9.0.107/libexec/webapps/myapp/WEB-INF/config/boot.rb:3)
	at org.jruby.RubyKernel.require(org/jruby/RubyKernel.java:1187)
	at RUBY.require(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:136)
	at RUBY.load_environment(uri:classloader:/jruby/rack/rails/environment3.rb:23)
	at RUBY.load_environment(uri:classloader:/jruby/rack/rails_booter.rb:83)
	at RUBY.<main>(<script>:1)

Workaround:
Avoid Git-based dependencies in the Gemfile when using Warbler.

Repro steps:

1. Use any Rails 7.1 app with JRuby 9.4.13.0
2. Add a gem via git: to the Gemfile
3. Package with warbler
4. Deploy to Tomcat
5. Observe failure during startup

[tillsc]

Just a quick note for anyone trying to test Warbler in its current state: due to this issue it's currently not really possible to use warbler as a Git dependency for testing. That makes it hard to test anything recent.

To work around that, I’ve published a temporary gem on RubyGems:
https://rubygems.org/gems/warbler-pre-release-tillsc

This gem includes two of my open pull requests:

• #564 – Gem.paths fix
• #562 – Fixes for Windows

This is not meant for production use.
I plan to yank the gem once the next Warbler release is out. But until then, it may be helpful for others who want to test recent changes or contribute.

Hope this helps!

[tillsc]

Once #567 is merged, the issue can also be reproduced using the integration tests.

Just add the following line to the Gemfile at
integration/rails7_test/src/main/ruby/Gemfile (the file will be available after the merge):

gem 'tzinfo', git: 'https://github.com/tzinfo/tzinfo.git', tag: 'v2.0.6'