bug#45854: 28.0.50; [feature/native-comp] autoload behavior different in the presence of errors

[Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Mauricio Collares <mauricio@collares.org> writes:

> This might be slightly off-topic (in the sense that the previous message
> stands alone and is not corrected by this one) but I have a related
> question to ask about the actual error I was hitting. To reproduce the
> error, one can use git-commitx.el and elpa2nix.el from the previous
> email and the following transientx.el file:
>
> ;;; transientx.el --- x -*- lexical-binding: t; -*-
>
> ;; Package-Requires: ((emacs "25.1"))
> ;; Package-Version: 0
>
> (require 'cl-lib)
> (require 'eieio)
>
> (defclass transient-suffix () ())
> (cl-defmethod transient--init-suffix-key ((obj transient-suffix)))
>
> (advice-add 'top-level :before 'identity)
>
> (provide 'transientx)
>
> ;;; transientx.el ends here
>
> That is, the "provide" line is uncommented but there's now an advice-add
> call. Running the following commands causes a problem similar to the one
> in the previous message:
>
> $ --batch -Q -l ~/elpa2nix.el -f elpa2nix-install-package /home/collares/transientx.el 
> $ --batch -Q --eval "(setq comp-eln-load-path '())" -l ~/elpa2nix.el -f elpa2nix-install-package /home/collares/git-commitx.el 
>
> git-commitx.el:6:1: Error: Cannot find suitable directory for output in ‘comp-eln-load-path’
> Done (Total of 0 files compiled, 1 failed, 2 skipped)
> Debugger entered--Lisp error: (error "transient--init-suffix-key is already defined as s...")
>   error("%s is already defined as something else than a gen..." transient--init-suffix-key)
>   cl-generic-ensure-function(transient--init-suffix-key)
>
> Apparently, advice-add caused native compilation to happen, and that
> failed because comp-eln-load-path was empty. This error plays a role
> similar to the lack of "(provide 'transientx)" in the previous email,
> leading to the second error which does not happen in trunk.
>
> In this email, however, I would like to address the first error. My
> question is: Is it possible to disable the native compilation caused by
> advice-add in the above example?

I think that's a bug, I believe `comp-enable-subr-trampolines' should
cover this case too.

> In Nix we run batch-native-compile
> separately after installing the package, and comp-eln-load-path is not
> set up until that point, so an option to disable all native compilation
> for a single batch session would be helpful. I tried setting
> comp-deferred-compilation and comp-enable-subr-trampolines to nil but
> still got the "Cannot find suitable directory for output in
> ‘comp-eln-load-path’" error with an empty comp-eln-load-path.
>
> Best,
> Mauricio
>
>
>
>

-- 
akrl@sdf.org