I think #20821 was closed prematurely; 7bcc6e9 added the riemann run script, but it seems to need a wrapper to provide java, among other things.
$ nix-shell -p riemann --run riemann --pure
/nix/store/2l3ickwgfp8521b5npkfq2468rd8f02z-riemann-0.2.9/bin/riemann: line 50: exec: java: not found
$ nix-shell -p riemann -p jre --run riemann --pure
Error: Could not find or load main class riemann.bin
remove riemann fix that doesn't work