Re: [PATCH v2] Add compat.el support to Org (was: [POLL] Use compat.el in Org? (was: Useful package? Compat.el))

[Ihor Radchenko <yantar92@posteo.net>]

Max Nikulin <manikulin@gmail.com> writes:

>> I know no other Emacs packages that manage dependencies using make.
>
> org-ql uses a helper shell script. org-roam and projectile use eldev 
> that is procedural, not declarative build system. I have not figured out 
> which way magit handles dependencies. I have no more ideas what projects 
> may involve unit tests and dependencies.

I see. Unfortunately, using third-party non-standard packages like
makem.sh or eldev will be more troublesome. We will need to sync Org
repo with them or demand users to install them separately.

Also, eldev is not on ELPA, and we cannot use it at all.

As for makem.sh, AFAIK, it will be even worse wrt network access - it
tries refreshing and downloading some packages by default, unless we
explicitly disable that feature. And under the hood, makem.sh anyway
does the same emacs --eval thing I used in the patch.

>>> I do not like the idea of network queries on every make.
>> Any better suggestions?
>
> Do not run install dependencies for regular targets like test or 
> compile. At least do not do it unless it is explicitly requested by 
> command line argument or a variable in local.mk

compat.el is required for "compile" target. Compilation will simply fail
with older Emacs. And "test" triggers "compile".

>> Actually, we need pkgdir := $(shell pwd)/pkg-deps.
>> CURDIR is wrong because default.mk will trigger evaluation in every make
>> sub-process as well.
>
> default.mk is included from top level Makefile only.

Not sure here. I just noticed that GITVERSION got re-calculated many
times when looking at debug output of make. (It was slowing things down
significantly). GITVERSION is in targets.mk though.

> By the way, it is 
> better to explicitly express that path is relative to top project 
> directory by defining e.g. top_builddir (or abs_top_builddir) at first and
>
> pkgdir = $(top_builddir)/pkg-deps

How to define top_builddir? If also via `pwd`, I see not much difference.

> Today I noticed the following trick in (likely stale) 
> https://github.com/org-roam/org-roam/blob/main/default.mk
>
> TOP := $(dir $(lastword $(MAKEFILE_LIST)))
>
> I have not realized if it is safe enough.

Reading through 6.14 Other Special Variables section of make manual, it
does not look safe - MAKEFILE_LIST may be altered by presence of includes.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>