ObserverPathnameExtension: only puts first 100 operations

Fixes https://github.com/Homebrew/homebrew/issues/44320#issuecomment-143951973

Closes Homebrew/homebrew#44440.

Signed-off-by: Xu Cheng <xucheng@me.com>

Library/Homebrew/extend/pathname.rb

@@ -473,6 +473,7 @@ module ObserverPathnameExtension
 
     def reset_counts!
       @n = @d = 0
+      @put_verbose_trimmed_warning = false
     end
 
     def total
@@ -482,33 +483,50 @@ module ObserverPathnameExtension
     def counts
       [n, d]
     end
+
+    MAXIMUM_VERBOSE_OUTPUT = 100
+
+    def verbose?
+      return ARGV.verbose? unless ENV["TRAVIS"]
+      return false unless ARGV.verbose?
+
+      if total < MAXIMUM_VERBOSE_OUTPUT
+        true
+      else
+        unless @put_verbose_trimmed_warning
+          puts "Only the first #{MAXIMUM_VERBOSE_OUTPUT} operations were output."
+          @put_verbose_trimmed_warning = true
+        end
+        false
+      end
+    end
   end
 
   def unlink
     super
-    puts "rm #{self}" if ARGV.verbose?
+    puts "rm #{self}" if ObserverPathnameExtension.verbose?
     ObserverPathnameExtension.n += 1
   end
 
   def rmdir
     super
-    puts "rmdir #{self}" if ARGV.verbose?
+    puts "rmdir #{self}" if ObserverPathnameExtension.verbose?
     ObserverPathnameExtension.d += 1
   end
 
   def make_relative_symlink(src)
     super
-    puts "ln -s #{src.relative_path_from(dirname)} #{basename}" if ARGV.verbose?
+    puts "ln -s #{src.relative_path_from(dirname)} #{basename}" if ObserverPathnameExtension.verbose?
     ObserverPathnameExtension.n += 1
   end
 
   def install_info
     super
-    puts "info #{self}" if ARGV.verbose?
+    puts "info #{self}" if ObserverPathnameExtension.verbose?
   end
 
   def uninstall_info
     super
-    puts "uninfo #{self}" if ARGV.verbose?
+    puts "uninfo #{self}" if ObserverPathnameExtension.verbose?
   end
 end