Below is a simple sketch that illustrates IDE behavior of which I was unaware:
#include < avr/io.h>
void setup() {
// put your setup code here, to run once:
}
void loop() {
// put your main code here, to run repeatedly:
}
This code does not compile on 1.5.8 of the IDE. Note that there is a blank space before the header file name in the #include directive. Remove that space and it compiles without error. Is this non-space in an #include specified in the Standard, or an implementation artifact?