unhandled exception when thowing exception from a function to another function - c++

Question

I have these class that I had mentioned in this question : catch in exception handling doesn't stop program and these is the coreNumbers functions that I had in there :
std::string info::coreNumbers()
{
int retValue;
std::string cpuSpeed = "";
getSSHState();
try {
num = exec_ssh_command(my_ssh_session, "ca /pro/cpuinfo | grep processor");
}
catch (MyException &err)
{
//exit(0);
throw err;
}
return num;
}
I have written "ca" in command on purpose. to get error and exception thrown. and these is my exec_ssh_command function :
std::string info::exec_ssh_command(ssh_session session, char *command) {
std::string receive = "";
int rc, nbytes;
char buffer[2000];
MyException errMsg;
try {
ssh_channel channel = ssh_channel_new(session);
if (channel == NULL)
{
receive = "Channel allocation failed.";
errMsg = MyException(receive);
throw errMsg;
}
rc = ssh_channel_open_session(channel);
if (rc != SSH_OK)
{
ssh_channel_free(channel);
receive = "Opening session channel failed.";
errMsg = MyException(receive);
throw errMsg;
}
rc = ssh_channel_request_exec(channel, command);
if (rc != SSH_OK) {
receive = "Channel's request executing failed.";
errMsg = MyException(receive);
ssh_channel_close(channel);
ssh_channel_free(channel);
throw errMsg;
}
nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
receive = buffer;
if (nbytes > 0)
{
receive.erase(nbytes - 1, 2000);
}
else
{
receive = "Error in command: not found or wrong syntax";
errMsg = MyException(receive);
throw errMsg;
}
while (nbytes > 0)
{
nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
}
if (nbytes < 0)
{
receive = "Error in reading data from channel. ";
errMsg = MyException(receive);
throw errMsg;
}
ssh_channel_send_eof(channel);
ssh_channel_close(channel);
ssh_channel_free(channel);
}
catch (MyException &err)
{
// std::cerr << err.what()<<flush;
throw err;
}
return receive;
}
when I run my code, I got unhandled exception in the throw that I have in coreNumbers function. after the exception in exec_ssh_command is thrown. am I misunderstood and using something wrong here?