In the --ignore-dir handling of trace.py, the following is done:

                s = s.replace("$prefix",
                              os.path.join(sys.base_prefix, "lib",
                                           "python" + sys.version[:3]))
                s = s.replace("$exec_prefix",
                              os.path.join(sys.base_exec_prefix, "lib",
                                           "python" + sys.version[:3]))

This does not do what is expected on 64-bit Fedora and newer Debian since the proper directory is /usr/lib64/python2.7 or /usr/lib/$triple/python2.7. Just the libsuffix can't be changed either since Fedora also has /usr/lib/python2.7 for arch-independent modules. It'd be nice if $prefix were replaced with the following directories from sysconfig.get_paths(): platstdlib, platlib, purelib, and stdlib.

It also erroneously replaces things like '$prefixpath'. It should probably do split the path on the path separators and only replace components that are equal to $prefix or $exec_prefix (so that the '$' can be escaped for directories named as such literally, but that would require a pass to parse the escapes).