Figured out the problem after a lot of red herrings....
Apparently something changed in a new version of the compiler, which means that the <algorithm> library needs to be manually included.
Code:
bitmapgriddropdown.cpp:299: error: ‘find_if’ was not declared in this scope
... find_if is part of the <algorithm> library.
So I just added
Code:
#include <algorithm>
to the includes section in bitmapgriddropdown.cpp and voila... it compiled.
I also found out that FTBFS is a relevant acronym = fails to build from source.