I am using cucumber+capybara in my tests
env.rb
Capybara.run_server = false
Capybara.default_driver = :selenium
World(Capybara::DSL)
In my test I am clicking on a link
Then /^I see deals on map$/ do
find("#dealmap").click
end
Above action is opening a layer (div) but the process stuck on find("#dealmap").click method. After 5 seconds I am getting following error
Timeout::Error (Timeout::Error)
/usr/lib/ruby/1.9.1/net/protocol.rb:146:in `rescue in rbuf_fill'
/usr/lib/ruby/1.9.1/net/protocol.rb:140:in `rbuf_fill'
/usr/lib/ruby/1.9.1/net/protocol.rb:122:in `readuntil'
/usr/lib/ruby/1.9.1/net/protocol.rb:132:in `readline'
/usr/lib/ruby/1.9.1/net/http.rb:2562:in `read_status_line'
/usr/lib/ruby/1.9.1/net/http.rb:2551:in `read_new'
/usr/lib/ruby/1.9.1/net/http.rb:1319:in `block in transport_request'
/usr/lib/ruby/1.9.1/net/http.rb:1316:in `catch'
/usr/lib/ruby/1.9.1/net/http.rb:1316:in `transport_request'
/usr/lib/ruby/1.9.1/net/http.rb:1293:in `request'
/usr/lib/ruby/1.9.1/net/http.rb:1286:in `block in request'
/usr/lib/ruby/1.9.1/net/http.rb:745:in `start'
/usr/lib/ruby/1.9.1/net/http.rb:1284:in `request'
./features/frontend/step_definitions/search_results_page.rb:2:in `/^I see deals on map$/'
features/frontend/search_results_page.feature:6:in `Then I see deals on map'
NOTE:
I have tried with increasing time but it is not solving the problem
I am unable to resolve the issue. Any suggestions ?
I think the problems comes from this line
Capybara.run_server = false
You will need this if you're running rack based tests. Remove it and re-run your tests.
If you're running web based tests you would want to keep this in there- and just because you're using Selenium doesn't mean you're running web bases tests. You're still running rack based tests but in a browser.
Related
I have a block of code that triggers my pry session via an integration test but no unit test exists. As such I'm not sure which test is exercising this code and need to run all tests each time I want it to trigger. Is there a way, in a pry session, to bubble up the test/test file? I do not need the _file_ that triggered the pry session.
My best solution has been to raise errors while in the pry session and then continue the test suite hoping that'll flub up a test and be able to locate that test in the testing report. This approach is a bit too much like stabbing in the dark.
You should be able to get the full call stack by simply invoking caller:
$ pry
[1] pry(main)> caller
=> ["/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:290:in `eval'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:290:in `evaluate_ruby'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:659:in `handle_line'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:261:in `block (2 levels) in eval'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:260:in `catch'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:260:in `block in eval'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:259:in `catch'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:259:in `eval'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/repl.rb:77:in `block in repl'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/repl.rb:67:in `loop'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/repl.rb:67:in `repl'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/repl.rb:38:in `block in start'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/input_lock.rb:61:in `__with_ownership'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/input_lock.rb:78:in `with_ownership'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/repl.rb:38:in `start'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/repl.rb:15:in `start'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/pry_class.rb:191:in `start'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/lib/pry/cli.rb:119:in `start'",
"/home/john/.gem/ruby/2.7.0/gems/pry-0.13.1/bin/pry:13:in `<top (required)>'",
"/home/john/.gem/ruby/2.7.0/bin/pry:23:in `load'",
"/home/john/.gem/ruby/2.7.0/bin/pry:23:in `<main>'"]
I am new to ruby programming. This is my first program in Watir. When I execute the code below, I am getting HTTP request path is empty (ArgumentError). Appreciate your help in fixing this error. I am accessing internet through proxy settings. I have added HTTP_PROXY variable in environment variables to http://myproxy.mynetwork.net:8008/
test.rb
require "watir"
require "rubygems"
require "rspec"
require "watir-webdriver"
puts "Hello,World...!"
#browser = Watir::Browser.new
#browser.goto("http://www.google.com")
#browser.close
puts "Browser should have been closed.."
Output
d:\>ruby test.rb
Hello,World...!
C:/Ruby193/lib/ruby/1.9.1/net/http.rb:1860:in `initialize': HTTP request path is
empty (ArgumentError)
from C:/Ruby193/lib/ruby/1.9.1/net/http.rb:2093:in `initialize'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/http/default.rb:71:in `new'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/http/default.rb:71:in `new_request_for'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/http/default.rb:35:in `request'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/http/default.rb:64:in `request'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/http/common.rb:40:in `call'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/bridge.rb:634:in `raw_execute'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/bridge.rb:99:in `create_session'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/remote/bridge.rb:68:in `initialize'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/firefox/bridge.rb:36:in `initialize'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/common/driver.rb:31:in `new'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver/common/driver.rb:31:in `for'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.41.0/lib/s
elenium/webdriver.rb:67:in `for'
from C:/Ruby193/lib/ruby/gems/1.9.1/gems/watir-webdriver-0.6.9/lib/watir
-webdriver/browser.rb:46:in `initialize'
from test.rb:8:in `new'
from test.rb:8:in `<main>'
Firefox browser window is getting opened. After that the address bar is not changing, and it is getting closed after some time.
net/http require a valid path. So you have to put a trailing slash at the end of the URL, like this:
#browser.goto("http://www.google.com/")
I have added HTTP_PROXY variable in environment variables to
http://myproxy.mynetwork.net:8008/
Removing my HTTP_PROXY variable from my (Windows) user/system env settings helped!
am not sure why this is causing the issue with selenium..
The following steps helped me:
Remove HTTP_PROXY and HTTPS_PROXY variables from my system (User Variables)
Restarted my terminal for the changes to take effect.
That's about it! No more errors!
I trying to get ruby to read the source of a url thats being hosted on my own computer. I've tried using open-uri gem with:
source = open('http://127.0.0.1:8000/wikipedia_en_all_nopic_01_2012/A/Mick%20Jagger.html', &:read)
With normal external urls this works fine but it raises multiple errors when i try to access the url im hosting on my computer. Does anyone have any idea how to this? Heres the command line error report:
/Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http/response.rb:357:in `finish': incorrect header check (Zlib::DataError)
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http/response.rb:357:in `finish'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http/response.rb:262:in `ensure in inflater'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http/response.rb:262:in `inflater'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http/response.rb:274:in `read_body_0'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http/response.rb:201:in `read_body'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:328:in `block (2 levels) in open_http'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http.rb:1415:in `block (2 levels) in transport_request'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http/response.rb:162:in `reading_body'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http.rb:1414:in `block in transport_request'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http.rb:1405:in `catch'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http.rb:1405:in `transport_request'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http.rb:1378:in `request'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:319:in `block in open_http'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/net/http.rb:853:in `start'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:313:in `open_http'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:723:in `buffer_open'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:210:in `block in open_loop'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:208:in `catch'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:208:in `open_loop'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:149:in `open_uri'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:703:in `open'
from /Users/rorycampbell/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/open-uri.rb:34:in `open'
from testurl.rb:6:in `<main>'
UPDATE: I'm using kiwix server to host the URL
Try using net/http instead.
require 'net/http'
source = Net::HTTP.get URI.parse('http://127.0.0.1:8000/wikipedia_en_all_nopic_01_2012/A/Mick%20Jagger.html')
Why do you want you use a URL if it's on the local machine? Why not just give the path?
That error sounds like there's something wrong with the actual file you're trying to parse, or the way it's being served by the way. From reading about Kiwix server it sounds like the latter...On the Kiwix site it says that it uses some type compression method called openzim which is most likely why open-uri can't find a way to parse it.
You could try nokogiri and see if it has a problem parsing it. But since it seems like you're trying to open/manipulate a zim file in ruby, I'd look for a zim library for ruby instead of trying to serve it.
Here:
https://github.com/chrisistuff/zim-ruby
I've never dealt with kiwix/zim, so I don't know if this one works but it was the only one the a google search for 'zim ruby' came back with.
I had the same problem with kiwix. I extracted all the URLs in a file called hrefs.txt (in my case it was the german project gutenberg) and used wget to download each of them:
f = File.open("hrefs.txt", "r")
f.each_line do |url|
#filename = url.split("/").last.gsub!(/[^A-Za-z]/, '')[0..-4]
system "wget #{url}"
end
f.close
I'm playing with Ruby / Sinatra at present and attempting to get HTTPS working.
I've taken a look at the rack:ssl gem here: https://github.com/josh/rack-ssl
It seems to be working when I run the application (as in redirecting to HTTPS), but nothing is displayed in the browser and the log comes up with the following error:
!! Invalid request
#!/usr/bin/env ruby
require 'rack/ssl'
require 'sinatra'
use Rack::SSL
get '/' do
'Hello World'
end
I'm not sure what to do from here.
Update:
Turned Thin Logging on in the sinatra app and got the following in the log:
!! Invalid request
Invalid HTTP format, parsing fails.
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/thin-1.5.1/lib/thin/request.rb:82:in `execute'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/thin-1.5.1/lib/thin/request.rb:82:in `parse'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/thin-1.5.1/lib/thin/connection.rb:39:in `receive_data'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `run_machine'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `run'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/thin-1.5.1/lib/thin/backends/base.rb:63:in `start'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/thin-1.5.1/lib/thin/server.rb:159:in `start'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/handler/thin.rb:16:in `run'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/sinatra-1.4.3/lib/sinatra/base.rb:1408:in `run!'
/Users/ashleycox/.rvm/gems/ruby-2.0.0-p247/gems/sinatra-1.4.3/lib/sinatra/main.rb:25:in `block in <module:Sinatra>'
Any help would be greatly appreciated, thank you.
I have a Sinatra application and DRb server object paired. When I try to pass the Sinatra params hash to a method on my server object I get DRb::DRbConnError …
DRb::DRbServerNotFound, yet the same method works when I pass a simple hash directly.
Why am I getting this error with the Sinatra params hash?
What are the easiest and most correct workarounds to fix this problem?
Here's a simple test case:
# server.rb
require 'drb'
class Server; def echo( hash ); hash; end; end
DRb.start_service 'druby://localhost:9007', Server.new
DRb.thread.join
# app.rb
require 'sinatra'
require 'drb'
SERVER = DRbObject.new_with_uri 'druby://localhost:9007'
get("/params"){ SERVER.echo(params).inspect }
get("/hash" ){ SERVER.echo(hello:'world').inspect }
With both of these running in their own processes:
phrogz$ curl http://localhost:4567/hash
{:hello=>"world"}
phrogz$ curl http://localhost:4567/params
DRb::DRbConnError - DRb::DRbServerNotFound:
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1653:in `current_server'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1721:in `to_id'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1050:in `initialize'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:642:in `new'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:642:in `make_proxy'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:559:in `rescue in dump'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:556:in `dump'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:603:in `block in send_request'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:602:in `each'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:602:in `send_request'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:903:in `send_request'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1196:in `send_message'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1088:in `block (2 levels) in method_missing'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1172:in `open'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1087:in `block in method_missing'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1105:in `with_friend'
/usr/local/lib/ruby/1.9.1/drb/drb.rb:1086:in `method_missing'
app.rb:4:in `block in <main>'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:1152:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:1152:in `block in compile!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:724:in `instance_eval'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:724:in `route_eval'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:708:in `block (2 levels) in route!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:758:in `block in process_route'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:755:in `catch'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:755:in `process_route'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:707:in `block in route!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:706:in `each'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:706:in `route!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:843:in `dispatch!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:644:in `block in call!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:808:in `instance_eval'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:808:in `block in invoke'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:808:in `catch'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:808:in `invoke'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:644:in `call!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:629:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.2/lib/rack/head.rb:9:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.2/lib/rack/commonlogger.rb:18:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/showexceptions.rb:21:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.2/lib/rack/methodoverride.rb:24:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:1272:in `block in call'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:1303:in `synchronize'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:1272:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.2/lib/rack/content_length.rb:13:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.2/lib/rack/chunked.rb:15:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/thin-1.2.11/lib/thin/connection.rb:84:in `block in pre_process'
/usr/local/lib/ruby/gems/1.9.1/gems/thin-1.2.11/lib/thin/connection.rb:82:in `catch'
/usr/local/lib/ruby/gems/1.9.1/gems/thin-1.2.11/lib/thin/connection.rb:82:in `pre_process'
/usr/local/lib/ruby/gems/1.9.1/gems/thin-1.2.11/lib/thin/connection.rb:57:in `process'
/usr/local/lib/ruby/gems/1.9.1/gems/thin-1.2.11/lib/thin/connection.rb:42:in `receive_data'
/usr/local/lib/ruby/gems/1.9.1/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run_machine'
/usr/local/lib/ruby/gems/1.9.1/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run'
/usr/local/lib/ruby/gems/1.9.1/gems/thin-1.2.11/lib/thin/backends/base.rb:61:in `start'
/usr/local/lib/ruby/gems/1.9.1/gems/thin-1.2.11/lib/thin/server.rb:159:in `start'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.2/lib/rack/handler/thin.rb:14:in `run'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/base.rb:1234:in `run!'
/usr/local/lib/ruby/gems/1.9.1/gems/sinatra-1.2.6/lib/sinatra/main.rb:25:in `block in <module:Sinatra>'
This is running under Ruby 1.9.2 on OS X, not that I think it makes a difference.
Short answer
You need to add
DRb.start_service
to app.rb before you try to make a remote call.
Explanation if you're interested
The Sinatra params hash is created with an associated block to handle the case when missing keys are referenced (here's the source). This means there's a Proc object associated with it.
Drb passes arguments back and forth by Marshalling them. However, from the Marshal docs:
Some objects cannot be dumped: if the objects to be dumped include bindings, procedure or method objects, instances of class IO, or singleton objects, a TypeError will be raised.
So there's going to be problems trying to pass this params hash about over the wire, as it contains an unmarshallable procedure object.
Now onto the Drb docs:
However, if an object cannot be marshalled, a dRuby reference to it is passed or returned instead. This will turn up at the remote end as a DRbObject instance. All methods invoked upon this remote proxy are forwarded to the local object, as described in the discussion of DRbObjects. This has semantics similar to the normal Ruby pass-by-reference.
Good news, it should still work. So what's wrong? A bit further on in the Drb docs we find this in the example code:
# Start a local DRbServer to handle callbacks.
#
# Not necessary for this small example, but will be required
# as soon as we pass a non-marshallable object as an argument
# to a dRuby call.
DRb.start_service
So what appears to be happening is Drb is trying to get a remote reference for the procedure object to pass to the server, but is unable as there's no Drb service set up client side.
Original answer
(I'll leave this here, it might me of interest. It was a resting point on my journey to figuring it all out. It's also a possible alternate solution. Interestingly, it appears that I'm now the more knowledgable person I referred to, at least with respect to the why.)
Here's a possible workaround. The problem seems to be with hashes created with a block to deal with missing keys (which Sinatra's params hash is), so you could extract the contents of the hash into a new one. params.clone and params.merge({}) both appear to retain the proc (you can check with Hash#default_proc), but {}.merge(params) (or merge!) gives you a nice clean hash that works with Drb.
So, in this example, do this:
get("/params"){ SERVER.echo({}.merge params).inspect
Why this happens with Drb and hashes with procs, and whether this is the easiest or most correct workaround, I'll leave to someone more knowledgable.