Rehash binaries on switch, forcing it to forget seen executables / lo…
…okup new path
For future reference, this was only part of the problem - and not really that much of a solution.
More relevant for the issue paneq mentions (and discussed in Yehuda's excellent blog post) are
ee8aee6 and 8940cac - although
the latter may be unneeded).
It required quite a lot of work to fix it. However its beyond my imagination how to write tests that can check against such cases :-)