Re: Use of system lisp when running freshly built emacs "in place"

[Adrian Robert]

On Apr 4, 2004, at 12:25 PM, Richard Stallman wrote:

>     will cause the freshly built emacs to load lisp files from
>     /usr/share/emacs .
>
> This is normal, since all versions of Emacs run files from
> /usr/share/emacs.  Since that directory isn't part of the
> distribution, it makes sense that even an uninstalled Emacs should use
> it.  Things would not be particularly better if this problem
> had showed up only when you someday install a new Emacs.

OK, then shouldn't the INSTALL instructions I quoted be changed to NOT 
make the reader think that if they run a freshly-built emacs in the 
build tree that they are just testing _that_ emacs (+lisp)?  The 
scenario that brought me to this problem was wanting to upgrade emacs, 
not install onto a blank system:

1) I have an existing emacs (21.3) installed

2)  I want to try out whether a CVS emacs is going to work for me, 
WITHOUT uninstalling my current emacs, which brings a lot of 
unnecessary pain if things don't work out.

3) If things DO work out, I would then uninstall existing emacs and 
install the new emacs.  In fact the use of /usr/share/emacs/<version> 
may even render the uninstall unnecessary, provided the 
/usr/share/site-lisp stuff works for both.

This doesn't seem like an uncommon situation.  I don't know if it is 
easy to change emacs to be able to run in a "local" mode loading 
everything from the source tree for testing (in other words, what the 
INSTALL instructions say it can do already), but if users need to "sudo 
mv /usr/share/emacs /tmp" (or at least "sudo mv 
/usr/share/emacs/site-lisp /tmp") before testing the copy they just 
built, then that's fine as long as it is in the instructions.


> I wonder about two things:
>
> 1. Why did you install in /usr/share/emacs a copy of mwheel.elc
> given that mwheel.el* is part of Emacs?

As mentioned above, I already had emacs-21.3 installed.  mwheel.elc was 
in this.  It was also, for some reason, in my site-lisp directory.  
This might be a local problem, but I think there are potentially many 
ways in which site-lisp could clash with a new emacs after working with 
an old, which is why I wanted to test the new emacs WITHOUT loading 
site-lisp or any other lisp from earlier emacs.  I am not sure whether 
the CVS emacs with "21.3.50" version number also tried to load lisp 
from /usr/share/emacs/21.3.  However since 21.3.50 is kind of a 
"static" version number, the problem will occur with the main lisp 
directory if trying to build and test a later CVS version when you have 
an earlier CVS version installed.


> 2. Why did that copy of mwheel.elc not define mouse-wheel-mode?  Is it
> that the function mouse-wheel-mode did not yet exist in that version
> of mwheel.el?

I assume something like this was the case.  I only have the .elc 
version of the old mwheel so could not examine the differences 
directly.


Adrian