Why does 'common.mk' convert build directory path to lowercase?

[ghost]

I do not quite understand the reasoning behind using:

Linux file-system is case sensitive, thus if you want to provide a different definition for BUILD_DIR that happens to have capital letters in it - it is going to build the files in a completely different directory than what you would expect, because:

Unless I have missed something that is obvious - I think $(call lc [...]) could be completely removed from common.mk.

Commit that introduced this problem: f34e229