px_proxy_factory_get_type() is declared in the public header proxy.h, but is not part of any ELF version definition (verdef) in libproxy.map. Third-party code would normally make use of this symbol via the PX_TYPE_PROXY_FACTORY macro, for example:

factory2 = g_boxed_copy (PX_TYPE_PROXY_FACTORY, factory);

or while defining a GObject property, something like

properties[PROXY_FACTORY] = g_param_spec_boxed ("proxy-factory", NULL, NULL, PX_TYPE_PROXY_FACTORY, ...);

Is this intended to be stable ABI that can be used by third-party code? If yes, I would have expected it to be part of a new verdef, which presumably at this point would have to be LIBPROXY_0.5.5. Or, if no, it should not be declared in the header and exposed as a public symbol.

Similarly, px_proxy_factory_copy() (the behind-the-scenes implementation of g_boxed_copy (PX_TYPE_PROXY_FACTORY, .)) is part of the public ABI even though it is not mentioned in proxy.h, and is not part of any ELF version definition. Is this intended to be stable ABI or not? If yes, I would have expected it to be part of a new LIBPROXY_0.5.5 verdef. Or, if no, it should not be exposed as a public symbol.