otawa-install.py ask me again and again to install in the current directory?

Once you have installed in a directory OTAWA_HOME, you have to use otawa-install.py from OTAWA_HOME/bin to add extension to OTAWA installation in OTAWA_HOME.

Command Line Tools

I get an error like:
ERROR: cannot build image of “…”: Missing dependency

OTAWA can only analyze self-contained program, that is, without external dependencies like dynamic libraries.
To prevent this, one has to compile the program with static libraries. With GCC, this is easily achieved using option “-static”.