With this ini config:
[env:nanoatmega328]
platform = atmelavr
board = pro16MHzatmega328
framework = arduino
upload_protocol = arduinoisp
trying to Upload using Programmer
I get the following error:
avrdude: Error: Could not find USBtiny device (0x2341/0x49)
If I try simple Upload
I get avrdude: Error: Invalid -P value: '/dev/cu.usbserial-1420'
The problem is within PlatformIO because Arduino IDE works like a charm.
macOS Catalina 10.15.3, Platformio core 4.3.4, home 3.2.3
Tried all tips from this thread: Can the Arduino ISP board be used with PlatformIO? - #33 by pfeerick