Re: [gentoo-user] GCC : another trap for the unwary

[Alan McKinnon]

On Sat, 8 Sep 2012 10:47:47 -0400
Philip Webb <purslow@××××××××.net> wrote:

> My new machine is working & compiles lightning-fast :
> it feels like the driver of a steam engine hurtling down the tracks
> (I've just finished a biography of J G Robinson, the UK loco
> designer).
>
> I've just recompiled most of the pkgs listed by 'emerge -ep system',
> but found a few problems :
>
> (1) Gcc 4.5.4 seems to require USE="cxx", not the previous "-nocxx",
> which was covered by "-*" at the beginning of my list in  make.conf .

USE=-*" is really not a good idea. It undoes all the sane defaults that
cascading profiles give you.

It is far far better to select the closest most appropriate profile
and add any desired flags that are not in the profile.

All you have succeeded in doing is removing the sane defaults and
forcing yourself to do it all manually. Which is really a whole lot of
heavy lifting Gentoo is designed to not require you to do. It's
Gentoo, not LFS :-)

 
> 4.5.4 compiled without "cxx" wouldn't recompile itself with "cxx" (!),
> but I found I could get around the problem by emerging 4.4.5 ,
> then using that to recompile 4.5.4 , after which 4.5.4 did recompile
> itself. It doesn't hurt to have  > 1  version of Gcc installed.

A sane profile would have prevented this from happening at all.

>
> (2) Libxml2 failed : I simply left it till tomorrow to find out why.
>
> (3) Groff + Openssh have an "X" flag : is this useful ?

for groff this builds gxditview, whatever that is. Probably an X
man-page viewer. I've never used it, I always run man in a terminal, I
suspect most other folk do too.

For openssh, the only thing this does is add xauth as a dependency.
For a workstation running X, you already have xauth.

So you can safely leave X enabled for both packages.


>     Python has a "build" flag, which suppressed many deps,
>     but now I'm back in my regular machine
>     'euses' issues a grim warning vs setting it.

Yes, you do not want to set USE="build" for python. You are not
building stage 1 images

>
> (4) The ancient distinction between 'world' / 'system'
>     seems to have degenerated into chaos :
>     some pkgs which clearly sb part of 'system' aren't,
>     while others -- eg virtuals -- have been added.

This was discussed to death about a year ago.

Specific pagers and editors are not in system anymore. Virtuals are.

The standard stage 3s give you a default pager and editor, so that if
you remove it, portage will add it right back in (and thereby not leave
you stranded up shit creek with no paddle in sight).

If you don't like nano as you editor and like me can't abide it's
existence, then merge vi and unmerge nano. The virtual is still
satisfied.

All of this is a good thing, it just takes a little thinking and
acceptance on your part.

>
> Incidentally, I've found out why the system creates many TTYs :
> they're the equivalent of GUI workspaces = desktops,
> allowing someone working without X to view different files etc.
> I'm continually struck by the genius of those who created UNIX in
> 1969 ...
>

They are there because Unix was from the very start designed to be a
multi-user, multi-tasking operating system and each user needs a tty. In
the 60s it was unthinkable to do it any other way. I don't think this
was any special genius on Thompson's part, it was the norm back then



-- 
Alan McKinnon
alan.mckinnon@×××××.com