In emacs, what does “terminal 7 locked, cannot read from it” mean?

Question

When using emacs, I sometimes get an error Terminal 7 is locked, cannot read from it. What does this error mean?

I am currently receiving an error message when I try to connect to an IRC server using erc, but I received it earlier, although I don’t remember why. When this happened earlier, I was able to try again, and eventually it worked, but now I get the same error every time.

I am starting a server session with emacs --daemonand connected various clients using emacsclient -t.

I searched for this online, but the only thing I can find is this . Besides the fact that I do not have an exact question, it does not have an accepted answer. :(

Answer 1

This error means that some Elisp code is trying to read from the minibuffer (for example), while in the middle of some other command in another “terminal” (for example, another tty). “In the middle” means, for example, that you are using the minibuffer in this other terminal or that you have pressed the prefix key.

I suggest you try to reproduce the reproducible way of causing this error, and then send it through M-x report-emacs-bug.