"Wrong type argument: consp, nil" from imenu

[sandinmyjoints]

Expected Behavior

• imenu works

Actual Behavior

• imenu--make-index-alist: Wrong type argument: consp, nil

Steps to Reproduce

1. call imenu on a markdown-mode buffer with the following content:

# A

### B

## C

Backtrace

Software Versions

• Markdown Mode: 2.5-dev
• Emacs: 28.0.50
• OS: macOS 10.14.6

[syohex]

I cannot reproduce this issue with both Emacs 28.0.50(2021/01/05 master branch) and 27.1.

I did

• emacs -Q -l markdown-mode.el test.md
• M-x imenu

Then no error happens. Could you tell us how to reproduce this issue in more detail ? cursor position, minimum configuration etc.

[rien333]

Are you by any change using the native-comp branch from emacs 28? I had a similar issue with that branch (I don't recall how I fixed it at the moment, however)

[sandinmyjoints]

I am, yes! Would definitely be interested in your fix.

[rien333]

I think that the following were among the steps that restored imenu to an usable state for me (in the context of markdown-mode):

1. Make sure to have an up-to-date emacs 28
2. Add (setq markdown-nested-imenu-heading-index nil) to your init.el

Why this works, I don't know. Could be that I did more stuff to fix this.

[wyuenho]

Does this issue really have to do with emacs 28?

[rien333]

Yes, but only in so far emacs 28 introduced the native comp feature, which at one point broke some imenu stuff.

[syohex]

I still cannot reproduce this issue with emacs master branch(2021/04/30) with native comp build flag.

[rien333]

@syohex could be that this (or some underlying) issue has been fixed by now, especially since the native-comp branch is under heavy development. In any case, I can't reproduce this issue anymore either.

[syohex]

Thanks for information. Please reopen if this issue happens again

[wyuenho]

I found this issue because I ran into it, please reopen. I'll report any debugging info here when I have some time to dig into it.

[eki3z]

yes, several days ago,the problem seems fixed by emacs28,but it appeared again after I update the native-comp branch...

[syohex]

@wyuenho please try to latest code. And this issue is not markdown-mode issue. If you still have problem, please report issue to emacs development mailing list.