Pack generation fails in bin/dev due to Bundler auto-exec interception (16.2.0.beta.11)

[justin808]

Pack Generation Fails When Running bin/dev Due to Bundler Auto-Exec Interception

Environment

• react_on_rails: 16.2.0.beta.11
• Ruby: 3.4.6
• Bundler: 2.4.17
• Rails: 8.1.1

Problem

When running bin/dev, pack generation fails with:

📦 Generating packs... ✅
Running `bundle react_on_rails:generate_packs` with bundler 2.4.17
Could not find command "react_on_rails:generate_packs".
❌ Pack generation failed

The pack generation actually succeeds (note the ✅), but then Bundler tries to execute bundle react_on_rails:generate_packs as a gem executable command instead of bundle exec rake react_on_rails:generate_packs, which fails.

Root Cause

In lib/react_on_rails/dev/pack_generator.rb, the run_via_bundle_exec method (lines 143-152) uses:

system("bundle", "exec", "rake", "react_on_rails:generate_packs")

When this is called from within an existing Bundler context (which is the case when running bin/dev), Bundler intercepts the system call and tries to parse the arguments. It sees "react_on_rails:generate_packs" and attempts to execute it as a gem executable via Bundler's auto-exec feature, rather than passing it through to rake.

The logic tries to avoid this by checking should_run_directly? (lines 66-73), which returns false when Rails isn't loaded. Since bin/dev doesn't load Rails (it shouldn't need to), it falls back to run_via_bundle_exec, triggering the bug.

Reproduction

# When already in a Bundler context:
require 'bundler/setup'
result = system('bundle', 'exec', 'rake', 'react_on_rails:generate_packs')
# => First runs the rake task successfully via direct invocation
# => Then Bundler intercepts and tries: bundle react_on_rails:generate_packs
# => Fails with "Could not find command"

Solution

The run_via_bundle_exec method should use Bundler.with_unbundled_env to prevent Bundler from intercepting the subprocess call:

def run_via_bundle_exec(silent: false)
  # Need to unbundle to prevent Bundler from intercepting our bundle exec call
  with_unbundled_context do
    if silent
      system(
        "bundle", "exec", "rake", "react_on_rails:generate_packs",
        out: File::NULL, err: File::NULL
      )
    else
      system("bundle", "exec", "rake", "react_on_rails:generate_packs")
    end
  end
end

def with_unbundled_context(&block)
  if defined?(Bundler)
    if Bundler.respond_to?(:with_unbundled_env)
      Bundler.with_unbundled_env(&block)
    elsif Bundler.respond_to?(:with_clean_env)
      Bundler.with_clean_env(&block)
    else
      yield
    end
  else
    yield
  end
end

Note: The with_unbundled_context method already exists in process_manager.rb (lines 120-129) and could be extracted to a shared module or copied to pack_generator.rb.

Workaround

Until fixed, users can:

1. Manually run bundle exec rake react_on_rails:generate_packs first
2. Then start foreman/overmind directly with the Procfile

Or patch the gem locally to add the with_unbundled_env wrapper.

Impact

This affects all users of bin/dev in react_on_rails 16.2.0.beta.11 when:

• Running from a Bundler context (which is typical)
• Rails isn't pre-loaded (which is normal for bin/dev)