Let me say this - I have absolutely no clue what this file does... i think I hit pp and tab on accident and it came up and I decided "what the hell is this" so i tried it.
I don't even know why kdesdk is installed on my system - probably for kdevelop which was removed (silly orphans).
Just thought I'd point this out
$ pacman -Qo `which pprof2calltree` /opt/kde/bin/pprof2calltree is owned by kdesdk 3.3.1-1
$ pprof2calltree /usr/bin/env: php: No such file or directory