I am getting an error:
gpg: no default secret key: No secret key
gpg: [stdin]: clearsign failed: No secret key
My secret keys are available to GPG.
Here's the answer: I am using latest gnupg version , but I have to use 0.44 gnupg interface version. I have reinstalled the gnupg.
Then no compilation errors were found. I am able to sign my message. but not able to send the request. The problem is I have not installed LWP::Protocol::Https module which is used by "Useragent" to send the request.( i came to know this that i have not installed the module by keeping simple print statements which shown the problem that LWP::Protocol::Https is not found). So i have installed LWP::Protocol::Https module through cpan. And i am good to go. Finally all is set :-)