Ulrich Müller <ulm@gentoo.org> writes:

> * doc/Makefile (org.texi, orgguide.texi): Fix parallel build failure.
> ---
>
> Forwarding Gentoo Linux bug #829055 <https://bugs.gentoo.org/829055>.
> When doing a parallel build (make -j16), a failure was observed when
> building the Texinfo documentation:
>
> make -C doc info
> make[1]: Entering directory '/var/tmp/portage/app-emacs/org-mode-9.5/work/org-mode-release_9.5/doc'
> emacs  -Q -batch --eval '(setq vc-handled-backends nil org-startup-folded nil)' 				      \
>   --eval '(add-to-list `load-path "../lisp")' \
>   --eval '(load "../mk/org-fixup.el")' 	      \
>   --eval '(org-make-manuals)'
> emacs  -Q -batch --eval '(setq vc-handled-backends nil org-startup-folded nil)' 				      \
>   --eval '(add-to-list `load-path "../lisp")' \
>   --eval '(load "../mk/org-fixup.el")' 	      \
>   --eval '(org-make-manuals)'
> Loading /var/tmp/portage/app-emacs/org-mode-9.5/work/org-mode-release_9.5/mk/org-fixup.el (source)...
> Loading /var/tmp/portage/app-emacs/org-mode-9.5/work/org-mode-release_9.5/mk/org-fixup.el (source)...
> ...lease_9.5/doc/org.texi locked by portage@local... (pid 55): (s, q, p, ?)? 
> Cannot resolve lock conflict in batch mode
> make[1]: *** [Makefile:31: orgguide.texi] Error 255
> make[1]: *** Waiting for unfinished jobs....
> make[1]: Leaving directory '/var/tmp/portage/app-emacs/org-mode-9.5/work/org-mode-release_9.5/doc'
> make: *** [mk/targets.mk:127: info] Error 2
>
> Fix by making org.texi a prerequisite of orgguide.texi, with an empty
> recipe.
>
>  doc/Makefile | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/doc/Makefile b/doc/Makefile
> index 96fda1445..7f996deae 100644
> --- a/doc/Makefile
> +++ b/doc/Makefile
> @@ -27,12 +27,14 @@ guide::		orgguide.texi org-version.inc
>  	../mk/guidesplit.pl $@/*
>  endif
>  
> -org.texi orgguide.texi:	org-manual.org org-guide.org
> +org.texi:	org-manual.org org-guide.org
>  	$(BATCH) \
>  	  --eval '(add-to-list '"'"'load-path "../lisp")' \
>  	  --eval '(load "../mk/org-fixup.el")' \
>  	  --eval '(org-make-manuals)'
>  
> +orgguide.texi:	org.texi
> +
>  org-version.inc:	org.texi
>  	@echo "org-version: $(ORGVERSION) ($(GITVERSION))"
>  	@echo "@c automatically generated, do not edit"  > org-version.inc

Thanks for the report and the suggestion.

Possibly a split of function org-make-manuals in org-make-manual and
org-make-guide and further create two single targets instead of the
current double target is more clear.

See the patch.

WDYT?