Error compiling Arduino 101

Hey guys!

Every time I open up my IDE and upload a sketch, I get this error:

C:\Users\avery\Documents\Arduino\libraries\Madgwick\src\MadgwickAHRS.cpp: In static member function 'static float Madgwick::invSqrt(float)':

C:\Users\avery\Documents\Arduino\libraries\Madgwick\src\MadgwickAHRS.cpp:218:20: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]

  long i = *(long*)&y;


C:\Users\avery\Documents\Arduino\libraries\Madgwick\src\MadgwickAHRS.cpp:220:16: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]

  y = *(float*)&i;


Sketch uses 28,372 bytes (18%) of program storage space. Maximum is 155,648 bytes.
Starting download script...
SUCCESS: Sketch will execute in about 5 seconds.

But the second time I compile, it gives no such errors. Should I be worried? Is there a bug in the board version compiler?

Thanks for ya time!

The first compile builds objects from all libraries as well as your sketch. Subsequent compile attempts only rebuild your sketch (and any new libraries referenced by your sketch) so you won't see those library warnings.


I see! That makes a lot of sense, because I was also wondering why the first compile was slower every time!

Thank you very much!

P.S. for the OCD of us who like 0 compile errors, is there a way to edit the library in order to solve this error?

Thanks again