Conditional library include statements incorrectly cause that library to be linked in.

[SlashDevin]

Consider this simplified example:

#if 0
  #include <NeoHWSerial.h>
#endif

void setup()
{
  Serial.begin( 9600 );
}

void loop() {}

This forces the NeoHWSerial library to be linked in, even when the condition is FALSE and there are no compile-time references to that library.

As a result, ISRs in HardwareSerial (via 'Serial') conflict with the same ISRs in the incorrectly linked-in NeoHWSerial. Simply commenting out the NeoHWSerial include statement removes the "require" of that library, and HardwareSerial links in correctly, as the only source of the ISRs:

#if 0
  //#include <NeoHWSerial.h>
#endif

void setup()
{
  Serial.begin( 9600 );
}

void loop() {}

I found this on 1.0.5 and reproduced it on 1.6.5r2

[matthijskooijman]

Could you try 1.6.6? I think this was solved in that version.

[SlashDevin]

Yep, fixed. Thanks!