os/linux/ld: harden brewed_ld_so_diagnostics against TypeError

I think this is a bug in Ruby, but I've no idea how to track it down. I
can reproduce it intermittently in a codespace when `brew install`ing a
large number of formulae.

To work around this:
- cache the return value of `brewed_ld_so_diagnostics` so that we can
  limit the number of calls to `IO.popen`
- retry once when we see a `TypeError`

Closes #17828.

Library/Homebrew/os/linux/ld.rb

@@ -7,13 +7,28 @@ module OS
     module Ld
       sig { returns(String) }
       def self.brewed_ld_so_diagnostics
+        @brewed_ld_so_diagnostics ||= T.let({}, T.nilable(T::Hash[Pathname, T.nilable(String)]))
+
         brewed_ld_so = HOMEBREW_PREFIX/"lib/ld.so"
         return "" unless brewed_ld_so.exist?
 
-        ld_so_output = Utils.popen_read(brewed_ld_so, "--list-diagnostics")
-        return "" unless $CHILD_STATUS.success?
+        brewed_ld_so_target = brewed_ld_so.readlink
+        @brewed_ld_so_diagnostics[brewed_ld_so_target] ||= begin
+          ld_so_output = Utils.popen_read(brewed_ld_so, "--list-diagnostics")
+          ld_so_output if $CHILD_STATUS.success?
+        end
 
-        ld_so_output
+        @brewed_ld_so_diagnostics[brewed_ld_so_target].to_s
+      rescue TypeError
+        # Workaround for intermittent `Error: no implicit conversion of false into String`
+        unless @retried_brewed_ld_so_diagnostics&.fetch(brewed_ld_so_target, false)
+          @retried_brewed_ld_so_diagnostics ||= T.let({}, T.nilable(T::Hash[Pathname, T::Boolean]))
+          @retried_brewed_ld_so_diagnostics[brewed_ld_so_target] = true
+          sleep 0.5
+          retry
+        end
+
+        raise
       end
 
       sig { returns(String) }