ivy-read-action does not work from ivy-hydra

[iquiw]

Steps.

1. Run emacs as

   $ emacs -Q -l ~/.emacs.d/elpa/hydra-0.14.0/lv.el -l ~/.emacs.d/elpa/hydra-0.14.0/hydra.el -l elpa.el -l colir.el -l ivy-overlay.el -l ivy.el -l swiper.el -l counsel.el -l targets/plain.el

2. Execute some command, such as M-x.
3. C-o a

Expected: Select action: and action candidates are displayed.
Observed: Nothing happens. And after C-g, keymaps gets weird (i inserts previous candidate of M-x).

The first bad commit seems 5ff5139.

[iquiw]

Related or not, ivy-hydra itself seems weird.

This is not related to the original issue, sorry.
It happens even before 5ff5139.