Might want to disclose that.
This is a big problem if you want reproducible builds with varying build directory.
https://lists.alioth.debian.org/pipermail/reproducible-build...
They definitely maintain software. There is a whole pile of packages that aren't maintained upstream any more that are still maintained in Debian, they write things like manual pages for commands that don't have then, they bash the build scripts into something that works on a whole pile of architectures the author never considers, they manage what is probably the worlds biggest issue track system, and then there is the security team producing patches for versions upstream no longer supports.
But probably it's just your wording. While they do maintain software, they are mostly concerned with packaging existing software, not writing new stuff.
(One of the packages I maintain in Debian is apparently dead upstream as of the last year or so, but even so I'm not very interested in becoming the new upstream and adopting big changes like a new build system.)
cxxflags = ${pkg-config opencv python --cflags --libs}
Furthermore I don't see the reason why you woudn't use buck for small projects. What makes you think buck is less suitable for small projects ?