Adafruit unified sensor library >= 1.1 blocks ISR(USART_RX_vect)

Other Hardware Sensors
1

After updating the Adafruit unified sensor library from 1.0.3 to 1.1.x I get compiler error on sketches using ISR (USART_RX_vect)

HardwareSerial0.cpp.o (symbol from plugin): In function Serial': (.text+0x0): multiple definition of __vector_18'
sketch/eg-ug.ino.cpp.o (symbol from plugin):(.text+0x0): first defined here
collect2: error: ld returned 1 exit status
exit status 1

In my sketches I am using the adafruit DHT sensor library which depends on the Adafruit unified sensor lib and this one uses the Serial stuff blocking vector_18.

Til version 1.0.3 no serial compiler problems.
One solution is to use another, non adafruit DHT library, but I would like to undertand why the unified sensor lib need Serial.

2

Shouldn't you be asking on Adafruit forum? It's their code.