bug#59882: 30.0.50; Compilation of ELPA packages during version upgrade (Org 9.6 ELPA upgrade from older ELPA version)

[Ihor Radchenko]

Hi,

I am writing as a follow-up of numerous errors reports on Org 9.6
upgrades.

Users commonly report issues upgrading Org mode via ELPA when an older,
non-built-in, version of Org is already installed and loaded.

The issue is well described in https://irreal.org/blog/?p=10996

People are commonly getting "invalid function `org-assert-version'",
which indicates compilation issue when `org-assert-version' macro is not
correctly recognized as a macro.

Similar errors have been reported in the past Org upgrades when we
introduced/changes some basic macros in Org.

I am not yet sure about the source of the error, but I suspect that it
might be something to do with package.el. May it be that M-x
package-install / package-reinstall does not unload the old package
versions upon installation? Or maybe there are some stale .elc files
lying around? Any other ideas?

P.S. Please, do not be diverted by the purpose of `org-assert-version'
macro. The origin of the error has nothing to do with it and could as
well happen with any other macro. It is just that we put this particular
macro into all the Org libraries now, making the problem obvious.

-- 
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>