tracking changes to env['PATH_INFO']

I am using validates_captcha ... which for reasons I do not understand
hooks into middleware.

validates_captcha is getting a bit upset (it dumps the stack and then
rescues itself) when it sees
  env['PATH_INFO']
equal to
  /undefined

Thus _something_ is setting env['PATH_INFO'] to undefined ... and I
would sure like to know what it is.

How can I set things up to see what line of code is doing that?

Ralph Shnelvar wrote:

I am using validates_captcha ... which for reasons I do not understand
hooks into middleware.

validates_captcha is getting a bit upset (it dumps the stack and then
rescues itself) when it sees
  env['PATH_INFO']
equal to
  /undefined

Thus _something_ is setting env['PATH_INFO'] to undefined ... and I
would sure like to know what it is.

How can I set things up to see what line of code is doing that?

Have you searched the code to see if there's an obvious reference to
that variable?

Have you tried stepping through with the debugger?

Best,