Custom Signal handling with gRPC?

Question

I have gRPC client implemented in C++ application. I also use sigaction as custom signal handling. On catching specific signals I send gRPC message to another gRPC server, then exists.

I have noted the following, my custom handlers are not invoked if I called grpc::CreateChannel before sigaction, instead I get Problem with executing command "/bin/bash /var/tmp/scl7oNQHY".

But I reversed the order of the execution, my handler is invoked. I have tested this behavior for SIGINT, SIGUSR1, SIGFPE and it's the same.

std::stringstream unixSocketName;
unixSocketName << "unix:///tmp/appname" << getpid() << ".sock";
std::shared_ptr<grpc::Channel> channel = grpc::CreateChannel(
        unixSocketName.str(), grpc::InsecureChannelCredentials());

int sig_no = SIGINT; //  I repeat this for multiple signals.
act.sa_sigaction = HandleSignal;
act.sa_flags = SA_SIGINFO;
auto status = sigaction(sig_no, &act, NULL);

Any insights ?

Thanks