I read it in 10720 revision. But why did you use word "will" (instead of "may") in the following snippet of text?:
<<On BSD distributions, if you use make instead of gmake, U++ compilation will fail>>

For example, this is not an issue for uppsrc/umk (which also exported for current tarball), where there are no files with "$" characters for dependencies and current revision builds fine with BSD make. This is an issue for uppsrc/ide or other projects, where files with "$" character(s) may be used.

Also, I noticed about build requirements:

Build requires: gmake gtk2 freetype2 libnotify llvm39 (clang++)

Maybe this is true for some *BSD operating systems without Clang compiler in base, but Clang 3.4.1 on FreeBSD 10.3 is capable to build uppsrc/ide and uppsrc/umk projects in tarball (was tested for 10703 revision):

% which clang++
/usr/bin/clang++
% clang++ --version | head -1
FreeBSD clang version 3.4.1 (tags/RELEASE_34/dot1-final 208032) 20140512

Installation of devel/llvm39 FreeBSD port is not mandatory for building of uppsrc/ide and uppsrc/umk (current revisions), at least on FreeBSD 10.3 amd64. But even if build/install it, the clang++39 (wrapper script; as part of devel/llvm39 FreeBSD port) may be used, because clang++ may be installed to different directory (which may be not exposed in (common) PATH, because other clang++ may exist in /usr/bin).