Hi,
The Linux tar ball (at least the 64 bit version) unpacks in home/ubuntu/DigisparkArduino-Linux64. Could you recreate the tar without the home/ubuntu part, please?
Also, the send/receive/digiusb in the 64bit version are actually 32bit applications and won't run by default on a 64 bit system (this was also the case with the previous release). They can easily be recompiled with the included source, so I would suggest including the actual 64 bit builds of them in the tarfile.
Regards, Paul Boven.