While reading the source file prelude-ivy.el in the Prelude modules directory, I saw that there was a warning associated with "here" in the last line, specifically that prelude-required-packages was not known to be a defined function.

I recognize that this is not exactly devastating but I am curious to understand better how to make a symbol "known to be defined" as a function. I tried a few things, like (require 'prelude-packages) but only moved the harmless warning around. I'm guessing that if I understand why this warning is being reported, a fix will be readily evident.


1 Answer 1


Your question is a little confusing, but I suspect you actually mean that you've byte-compiled the prelude-ivy.el library (as opposed to "reading the source file"), and that the compiler has produced a warning that the function prelude-require-packages is not known to be defined (n.b. not "prelude-required-packages", which does not appear anywhere in the file; and the warning would be quite specific about it being a function, rather than a "symbol", which is not known to be defined).

The warning would look like this:

In end of data:
prelude-ivy.el:71:1:Warning: the function ‘prelude-require-packages’ is not known to be defined.

(And for future reference, if you have a question about a warning or error message, you should always copy and paste that message into your question -- doing so here would have eliminated all the confusion.)

The message tells us that the byte-compiler got all the way through the file and never encountered a definition for that function, even though it was used earlier in the file:

(prelude-require-packages '(ivy swiper counsel))

The warning (which will indeed be harmless in practice) can be silenced by informing the byte-compiler where the function prelude-require-packages is defined:

(declare-function 'prelude-require-packages "prelude-packages")

See C-hig (elisp)Declaring Functions

  • Thank you both Drew and Phils for providing an answer and teaching how to write a better question. Both are very much appreciated.
    – pajato0
    Jul 21, 2018 at 3:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.