Comment 2 for bug 406113

See also https://code.edge.launchpad.net/~mbp/bzr/406113-extension-warnings/+merge/9410

John points out we should give just one message, not one for every missing extension.

Plugins may add compiled extensions, so ideally we would not have a static list of 'the extensions for Bazaar'.

Extensions may fail to load for reasons other than the file not being present.

At the moment we have no concept of 'all the extensions bzr uses'. We could poke through the bzrlib directory and find either .c, .pyx or extension libraries, though that might not cover extensions needed by plugins. Alternatively, we can have a statically maintained list,

Bug 131019 asks that we show the extensions in --version. That seems to imply probing for extensions that wouldn't normally be loaded to show the version.