Description
It seems that the new "Please select a port before upload"-message that was added in #7958 breaks uploads to port-less devices, such as the digispark boards. These devices use a custom uploader tool that uses a custom USB protocol through libusb rather than a serial port.
On a new install, there would be no need to select a serial port with these boards. However, the newly added message is still shown, and uploading is prevented. On a system without serial ports, where a port has never been selected before, this completely prevents users from uploading their sketches.
Note that I haven't confirmed this problem myself, this report is based on a report from a user in #arduino a few days ago. However, from how I understand the code works, I expect this issue exists as described.
To fix this, I guess the IDE should become aware of whether a board needs a serial port to upload. One easy way would be to see if the upload recipe uses the serial port name (the digispark core does not, though that feels a little bit fragile.