why the git version? 0.24b (in nixpkgs) was broken. using 0.25rc1 gave the same error (gcc 4.6 related) Both these versions are over a year old and lots of commits were made after that, including something that fixed building on nix.
[1] https://github.com/apenwarr/bup Signed-off-by: David Guibert <david.guibert@gmail.com> svn path=/nixpkgs/trunk/; revision=28497