Script/console is hanging, Observer issue...?

tonyfromky · September 21, 2018, 1:50am

After weeks of working fine, yesterday script/console started hanging
upon startup, right after printing “Loading Development Environment.”
I waited several minutes and control-C’d, and got this:

^C/usr/local/lib/ruby/1.8/singleton.rb:150:in sleep': Interrupt from /usr/local/lib/ruby/1.8/singleton.rb:150:in_instantiate?’
from /usr/local/lib/ruby/1.8/singleton.rb:106:in instance' from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/observer.rb:38:ininstantiate_observers’
from
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/observer.rb:36:in
each' from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/observer.rb:36:ininstantiate_observers’
from
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:212:in
load_observers' from /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:108:inprocess’
from
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:43:in
send' ... 51 levels... from /usr/local/lib/ruby/1.8/irb/init.rb:250:inload_modules’
from /usr/local/lib/ruby/1.8/irb/init.rb:21:in setup' from /usr/local/lib/ruby/1.8/irb.rb:54:instart’
from /usr/local/bin/irb:13

I looked in environment.rb and there’s only one observer. I checked it
against SVN and it hasn’t changed in weeks.

I did some debugging and found that the hang is related to this line in
inflector#constantize:

Object.module_eval("::#{$1}", FILE, LINE)

     # File vendor/rails/activesupport/lib/active_support/inflector.rb,
line 245
245:   def constantize(camel_cased_word)
246:     unless /\A(?:::)?([A-Z]\w*(?:::[A-Z]\w*)*)\z/ =~
camel_cased_word
247:       raise NameError, "#{camel_cased_word.inspect} is not a valid
constant name!"
248:     end
249:
250:     Object.module_eval("::#{$1}", __FILE__, __LINE__)
251:   end

What does this line do? The class name being observed is “User”

tonyfromky · September 21, 2018, 11:04pm

Update.

I deleted the source code and re-checked it from SVN. Magically,
script/console started behaving. I have no explanation.

However, now it seems mongrel and webrick are experiencing the same
issue. Mongrel won’t come up, it just stalls after “** Starting Rails
with development environment…” A Ctrl-C kills it.

Webrick, however, when Ctrl-C’d, produces the same stack trace as seen
below.

Tony Fromky wrote:

After weeks of working fine, yesterday script/console started hanging
upon startup, right after printing “Loading Development Environment.”
I waited several minutes and control-C’d, and got this:

^C/usr/local/lib/ruby/1.8/singleton.rb:150:in sleep': Interrupt from /usr/local/lib/ruby/1.8/singleton.rb:150:in_instantiate?’
from /usr/local/lib/ruby/1.8/singleton.rb:106:in instance' from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/observer.rb:38:ininstantiate_observers’
from
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/observer.rb:36:in
each' from /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/observer.rb:36:ininstantiate_observers’
from
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:212:in
load_observers' from /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:108:inprocess’
from
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:43:in
send' ... 51 levels... from /usr/local/lib/ruby/1.8/irb/init.rb:250:inload_modules’
from /usr/local/lib/ruby/1.8/irb/init.rb:21:in setup' from /usr/local/lib/ruby/1.8/irb.rb:54:instart’
from /usr/local/bin/irb:13

I looked in environment.rb and there’s only one observer. I checked it
against SVN and it hasn’t changed in weeks.

I did some debugging and found that the hang is related to this line in
inflector#constantize:

Object.module_eval("::#{$1}", FILE, LINE)
     # File vendor/rails/activesupport/lib/active_support/inflector.rb,
> line 245
> 245:   def constantize(camel_cased_word)
> 246:     unless /\A(?:::)?([A-Z]\w*(?:::[A-Z]\w*)*)\z/ =~
> camel_cased_word
> 247:       raise NameError, "#{camel_cased_word.inspect} is not a valid
> constant name!"
> 248:     end
> 249:
> 250:     Object.module_eval("::#{$1}", __FILE__, __LINE__)
> 251:   end
What does this line do? The class name being observed is “User”