Re: Integrating package.el

[Jonas Bernoulli <jonas@bernoulli.cc>]

(I am rather confused by the mixture of quoting styles.)

>>> Emacs could recognize the Version header and always track it internally
>>> when it loads a library file, maybe with a (version . "1.2") in the
>>> load-history.  That would help a lot, I think.

Absolutely. However this information is missing from a lot of
libraries. Also even
if library contain version information it is still uncommon that
libraries state what
version of their dependencies are actually required.  Cedet contains something
like this - has this portion of cedet been merged into 23.2?

If such an extended `require' form (or similar standardized information in the
library header) are not adopted there is no way to automatically extract this
information.

This means that maintainers of package repositories have to figure it
out manually
or just leave this information out completely.  I am mirroring 2100
packages - I won't
do it manually.

> SM> I personnally don't care about the behavior if the user tries to
> SM> activate two different versions of the same package in a given session.

If I remember correctly what he meant to say was that loading multiple versions
is a user error. Having multiple versions installed is still an option
as is choosing
a particular version by the user (as opposed to the sysadmin) at runtime.

> OK.  But I still think Emacs should record the version as I suggested
> whenever it finds it in a .el/.elc file.  It would help resolve many
> annoying user-level bugs by showing exactly what version of the library
> was loaded, not implied from the directory but directly from the version
> header.  Does that require lots of changes?

I agree. But as explained above this still doesn't help the package manager to
determine which version of a dependency is required.

-- Jonas