Checking /usr/local/ before upgrading

[Fergal Daly]

On 31/10/2007, Christofer C. Bell <christofer.c.bell at gmail.com> wrote:
> On 10/30/07, Jan Claeys <lists at janc.be> wrote:
> > Op dinsdag 30-10-2007 om 10:46 uur [tijdzone +0100], schreef Vincenzo
> > Ciancia:
> > > I expected anything out of this thread, but people defending the idea
> > > that keeping /usr/local/lib in the library path during system upgrades
> > > is a good idea. I can accept to have problems *after* the upgrade, but
> > > not to be left with an unusable system just because I had stuff in
> > > /usr/local and that's my fault.
> >
> > Everyone can answer on this list with what is their personal opinion, so
> > why are you surprised to to hear any particular opinion?   :)
>
> From the FHS document:
>
> "The /usr/local hierarchy is for use by the system administrator when
> installing software locally. It needs to be safe from being
> overwritten when the system software is updated. It may be used for
> programs and data that are shareable amongst a group of hosts, but not
> found in /usr."[1]
>
> If you rename it, move it, or otherwise get rid of it, you're
> "overwriting" the contents of /usr/local.  You are "removing" it from
> integration with the system.  The onus is on the system administrator
> to test their software to ensure that it works with a new operating
> system release.  If the system administrator doesn't do that, it's not
> the fault of the operating system that the software doesn't work.  If
> it's unknown if the software will work or the system administrator
> wants to preserve /usr/local while not having it visible during the
> upgrade, then they need to take care of that themselves before
> performing the upgrade.
>
> Are you suggesting the installer present a message saying something
> like, "The contents of /usr/local may or may not be compatible with
> this release.  Would you like to rename /usr/local to /usr/local.save
> now and verify compatibility later? [Yes] [No]"? While I don't have an
> issue with that, will doing so break compatibility with the FHS?

That will not work if /usr/local is a mount point. What's wrong with
just having all the system scripts ignore the contents of /usr/local
or at the very least, put it last in the search path?

F

> [1] http://www.pathname.com/fhs/pub/fhs-2.3.html#PURPOSE23
>
> --
> Chris
>
> "To announce that there must be no criticism of the president, right
> or wrong, is not only unpatriotic and servile, but is morally
> treasonable to the American public," said President Theodore
> Roosevelt.
>
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