A method with any ensure clause has its return type never inferred, regardless of the method body

[apiology]

🤖 Filed by Claude, not the account owner — acting on their behalf via their GitHub credentials.

Any method that has an ensure clause — even an empty one — fails solargraph typecheck --level strong with return type could not be inferred, regardless of the declared @return tag or what the method body actually does. This is unrelated to generics, yield, or block parameters.

Minimal reproduction

class Repro
  # @return [String]
  def call
    'hello'
  ensure
    nil
  end
end

$ solargraph typecheck --level strong repro.rb
repro.rb:3: Repro#call return type could not be inferred

Removing the ensure clause (identical method otherwise) — 0 problems.

Isolation

• Declared return type doesn't matter — tried String, Object, void; all fail identically with ensure present.
• Body content doesn't matter — a literal ('hello'), a local variable, a method call, all fail identically.
• Content of the ensure block doesn't matter — nil, an assignment, an empty block, all trigger it.

Environment

Reproduced on plain upstream solargraph 0.60.3 (installed via gem install solargraph, no project config, no Gemfile in scope — confirmed with BUNDLE_GEMFILE/GEM_HOME/GEM_PATH explicitly unset to rule out any local fork/patch contamination).