What about devtodo ?
Reading your summary, it seems that the todo.txt virtual package
is well specified, but the todo one is not.
Do you envision to have packages depending on todo and then use the
todo binary ?
No. This is a means to allow topydo and todotxt-cli to use "todo" without
crowding devtodo. I believe this meets the definition of a virtual package
in the Policy.
I do see the desirability for packages to be able to Depend on todo.txt, with
an expectation of the command line format beneath (e.g. support for a
todo.txt schema).