Re: Build failures on kernel version changes

[Julio Merino <jmmv%julipedia.org@localhost>]

On 1/11/12 7:52 PM, David Young wrote:
> On Wed, Jan 11, 2012 at 07:30:31PM -0500, Julio Merino wrote:
> > Hello,
> >
> > I always run "update builds" of the tree (in a cron job, for that
> > matter) and, whenever the kernel version changes, the build breaks
> > as shown here:
> >
> > Configuring in ./libiberty
> > configure: loading cache ./config.cache
> > configure: error: `build_alias' has changed since the previous run:
> > configure:   former value:  `x86_64-unknown-netbsd5.99.55'
> > configure:   current value: `x86_64-unknown-netbsd5.99.58'
> > configure: error: `host_alias' has changed since the previous run:
> > configure:   former value:  `x86_64-unknown-netbsd5.99.55'
> > configure:   current value: `x86_64-unknown-netbsd5.99.58'
> > configure: error: in `/home/builder/obj/usr/src/tools/gcc/build/intl':
> > configure: error: changes in the environment can compromise the build
> > configure: error: run `make distclean' and/or `rm ./config.cache'
> > and start over
> > configure: loading cache ./config.cache
> > nbgmake: *** [configure-intl] Error 1
> > nbgmake: *** Waiting for unfinished jobs....
> > configure: error: `build_alias' has changed since the previous run:
> > configure:   former value:  `x86_64-unknown-netbsd5.99.55'
> > configure:   current value: `x86_64-unknown-netbsd5.99.58'
> > configure: error: `host_alias' has changed since the previous run:
> > configure:   former value:  `x86_64-unknown-netbsd5.99.55'
> > configure:   current value: `x86_64-unknown-netbsd5.99.58'
>
> Isn't this a fairly new failure mode, too?  That is, new in the last 2
> or 3 years?

Dunno.  It might be; I just know I have been seeing this for a looong 
time and never thought about finding an automated "solution".

> > Could we do something to automatically "workaround" this issue by,
> > e.g. rebuilding all components that are affected by a kernel version
> > change?
>
> Are you asking for permission? :-)

Well, I'm asking first if this makes any sense at all.  I don't know 
exactly what the error above is trying to prevent, so I'm not aware of 
what would need cleaning for this to work safely.