Nasty bug with binary files, Rails and erb.rb – how to fix it

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Tags: bugs English Geeky rails
Categories: English Geeky

OK, so I happily hack away on my  Rails application on a Debian box with Ruby 1.8.7 and Rails 2.1.0, and then deploy to a Fedora 8 server with Ruby 1.8.6 and Rails 2.2.2. All of a sudden a particular release causes Passenger to spit an error page on application startup. The key error was:

undefined method \`empty?’ for nil:NilClass

Now I’m combing all over my code to find where I’m using “empty?” but I’m sure it’s somewhere that gets run on application startup, otherwise it wouldn’t show up when Passenger tries to start the application. But I find nothing and I’m about to shoot myself.

Following the trace I end up hacking Ruby’s erb.rb file, as there appear to be some bugs in this; indeed, this one from 1.8.6 is different from what I have in 1.8.7, so the app runs fine here. I try to fix instances where empty? might get called on a nil object, but after fixing 3 of these the app stops responding altogether. Hmm, so something, somewhere, depends on erb.rb’s buggy behavior. Best to leave it alone.

HOWEVER, on the deployment server, running with script/server works fine; it’s only when using Passenger that things blow up.

Finally I find this thread that points me in the right direction:

One of the users dropped some
JPEG files into the /app/views/static directory, and that seems to be
jamming up the works with 2.2.2.

Indeed, as part of my last set of revisions, I’d left several samples of static content I was converting into dynamically generated pages; sure enough, they included JPGs and whatnot. Just to be safe, I decided to move the entire directory into public to avoid any problems.

Now the app runs just peachy and I only wasted 2 hours chasing down this bug. Thanks to the guys at Nabble!

Eventually it all boils down to this Rails bug reported at Lighthouse. So hopefully it’ll be fixed soon. In the meanwhile, keep binary files out of your views subtree.

I’m attaching the entire Passenger error page, in case it’s useful to anyone. Mainly so that Google can find it faster for other people with this problem.

Ruby on Rails application could not be started

These are the possible causes:

  • There may be a syntax error in the application’s code. Please check for such errors and fix them.
  • A required library may not installed. Please install all libraries that this application requires.
  • The application may not be properly configured. Please check whether all configuration files are written correctly, fix any incorrect configurations, and restart this application.
  • A service that the application relies on (such as the database server or the Ferret search engine server) may not have been started. Please start that service.

Further information about the error may have been written to the application’s log file. Please check it in order to analyse the problem.

Error message:
undefined method `empty?’ for nil:NilClass
Exception class:
NoMethodError
Application root:
/var/www/spcccdec/releases/20090227005857
Backtrace:
# File Line Location
/usr/lib/ruby/1.8/erb.rb 478 in `scan’
1 /usr/lib/ruby/1.8/erb.rb 524 in `compile’
2 /usr/lib/ruby/1.8/erb.rb 691 in `initialize’
3 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/template_handlers/erb.rb 51 in `new’
4 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/template_handlers/erb.rb 51 in `compile’
5 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/template_handler.rb 11 in `call’
6 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/renderable.rb 21 in `_unmemoized_compiled_source’
7 /usr/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/memoizable.rb 57 in `compiled_source’
8 /usr/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/memoizable.rb 25 in `__send__’
9 /usr/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/memoizable.rb 25 in `memoize_all’
10 /usr/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/memoizable.rb 22 in `each’
11 /usr/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/memoizable.rb 22 in `memoize_all’
12 /usr/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/memoizable.rb 17 in `freeze’
13 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 88 in `reload!’
14 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 102 in `templates_in_path’
15 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 100 in `each’
16 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 100 in `templates_in_path’
17 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 86 in `reload!’
18 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 78 in `load’
19 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 109 in `load’
20 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 109 in `each’
21 /usr/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_view/paths.rb 109 in `load’
22 /usr/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/initializer.rb 357 in `load_view_paths’
23 /usr/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/initializer.rb 182 in `process’
24 /usr/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/initializer.rb 112 in `send’
25 /usr/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/initializer.rb 112 in `run’
26 ./config/environment.rb 13
27 /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb 31 in `gem_original_require’
28 /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb 31 in `require’
29 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/railz/application_spawner.rb 254 in `preload_application’
30 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/railz/application_spawner.rb 214 in `initialize_server’
31 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/utils.rb 179 in `report_app_init_status’
32 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/railz/application_spawner.rb 203 in `initialize_server’
33 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/abstract_server.rb 166 in `start_synchronously’
34 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/abstract_server.rb 135 in `start’
35 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/abstract_server.rb 112 in `fork’
36 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/abstract_server.rb 112 in `start’
37 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/railz/application_spawner.rb 179 in `start’
38 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/spawn_manager.rb 222 in `spawn_rails_application’
39 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/spawn_manager.rb 217 in `synchronize’
40 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/spawn_manager.rb 217 in `spawn_rails_application’
41 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/spawn_manager.rb 126 in `spawn_application’
42 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/spawn_manager.rb 251 in `handle_spawn_application’
43 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/abstract_server.rb 317 in `__send__’
44 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/abstract_server.rb 317 in `main_loop’
45 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/lib/passenger/abstract_server.rb 168 in `start_synchronously’
46 /usr/lib/ruby/gems/1.8/gems/passenger-2.0.6/bin/passenger-spawn-server 46

EPIC FAIL: the lack of road culture in Mexico City

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Tags: English mexico
Categories: English Pinche México

(c) La Jornada, 2009

I’ve written before about how people in Mexico have zero road culture, which leads to a complete breakdown of road infrastructure. A lot of this infrastructure’s correct operation depends on people abiding by the law. Yet most people do not. Usually the consequences are from nil (parking in a handicapped space for a moment, leaving your car double-parked, parking in front of a house’s garage) to a relatively minor fine (parking illegally and THEN getting towed because the  tow truck happened to be nearby).

However, when physical security of moving vehicles is dependent on the assumption that people will respect the law, things do indeed break down.

The metrobús is a Bus Rapid Transit system, which opened in 2005 in one important Mexico City avenue, and has enjoyed (in my opinion) great success, reducing transport times, improving traffic flow for private vehicles, and getting rid of dangerous Peseros along Insurgentes avenue. Everybody in Mexico knows Peseros are the worst offenders when it comes to traffic violations, where they blatantly run red lights, invade lanes, and generally do what they please without regard for others. So their sole disappearance was a blessing.

The price to be paid for this was that, since the metrobus runs on central lanes, left turns are forbidden along the avenue’s 26-km length. The reason is obvious: at the very least a significant disruption of traffic might occur if the bus has to stop for a car that’s trying to left-turn. At worst, the metrobus, a double-length behemoth, might hit another car with deadly consequences.

It’s been 3 years of the Metrobus operating, and this year a second line (running along eje 4 sur) was opened. This has caused an uproar because it appears this line has been misdesigned, creating several “death traps” and spots where, due to lack of space, cars and pedestrians have a tough time getting through. This has led to 18 accidents since the new line opened.

Some asshole in the government who needs urgent math lessons said that “98% of accidents involving the metrobus are due to private car driver’s imprudence”. For starters, 98% of 18  is 17.64, and assigning partial blames is absurd.

Anyway, what’s indeed clear is that most of the accidents are due to lack of culture by drivers. The all-too-common notion that “nobody wants to have an accident and if I just swerve violently in front of someone they’ll stop and swear at me but I’ll get my way” fails when the “someone” is a 15-ton monster  traveling at 60 km/h with 30-meter stopping distances.

Sometimes, then, images are worth a thousand words, so I’ll leave you with the conclusion that while it’s necessary to guarantee that people operating a car need to have a minimum of road education, it’s also not going to happen because the “it’s ok just this one time” mentality rules, and as long as we’re giving driving licenses to anyone without a driving test (right, in Mexico there are no driving tests, you just pay for your license and you get it) things like this are going to happen. I also leave you with an eye-opening video of exactly whose fault it was for the accident, a picture of which is at the top of this message.

Mexico’s secretary of the interior dies in plane accident

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Tags: English politics
Categories: English Pinche México

Or, was it an accident? There’s plenty of speculation about the plane crash that cost Juan Camilo Mouriño, Mexico’s secretary of the interior (Secretario de Gobernación) and (so far) 12 other people their lives. Theories ranging from a simple accident to a narco-fueled vendetta abound.

But the fact is that the tragedy should be looked at from a humanitarian point of view. 13 dead and over 40 injured, 3 of which might also die in the next few days. It’s a time for mourning, yes, but for us to mourn for all the people who died, not just mr. Mouriño; a time for the entire mexican society to give their support to the families of the deceased, just as we would in any other tragedy.

Let me be cold-hearted for a while and state this: Mouriño’s death will not have a great impact for Mexico or even for president Felipe Calderón’s team, his plans or aspirations. Because for all the power his position brought, Mouriño himself was a rather grey politician. So yes, let the president give speeches about how we lost a “great mexican” (he was born in Spain so even that is debatable). But the truth is, Mouriño will get replaced by someone else, with similar political prowess, capabilities, aspirations and a similar position to further Calderón’s plans, whatever they are. And in the public eye, Mouriño will fade and then disappear, to become a footnote like Ramón Martín Huerta (whose name, incidentally, has resurfaced in connection with the Mouriño tragedy).

He will disappear, that is, in the eyes of everybody but his family and friends: these people didn’t just witness the death of a high-ranking government officer; they lost a friend, a father, a husband, and a son. To them, and to all the relatives of the deceased, the tragedy has a very personal feel. This is the level at which us normal people can empathize and understand the magnitude of what happened, for any loss of human life is to be regretted. So indeed, let our prayers (for those who pray) and our condolences and best wishes be with mr. Mouriño’s family, as well as with those of all the others who lost their lives or were injured in the tragedy.