[SOLVED]I can't use "multilib" USE flag for gcc, why?

Message

ccgoo · Post by **ccgoo** » Sat Aug 11, 2007 5:19 pm

Today, I casually found my gcc does not support "multilib".

When I executed the command:
emerge -p gcc
I saw the output: [ebuild NS ] sys-devel/gcc USE="xxx xxx xx (-multilib) ..."

I think my gentoo profile is default multilib-enabled. I can emerge many software including eml-* packages.
My make.profile is linked to /usr/portage/profile/default-linux/amd64/2007.0

I wanna know why gcc is with (-multilib)。

Post by **NeddySeagoon** » Sat Aug 11, 2007 5:25 pm

ccgoo,

Thats an odd profile to be using. Its intended as a parent to either

/usr/portage/profile/default-linux/amd64/2007.0/desktop or
/usr/portage/profile/default-linux/amd64/2007.0/server
so many use flags that you could have obtained by defualt will be unset. You can set them yourself of course, so its not an error to use
/usr/portage/profile/default-linux/amd64/2007.0/desktop, just a little odd.

(-multilib) means that the flag is disabled in your profile and you cannot enable it.

ccgoo · Post by **ccgoo** » Sun Aug 12, 2007 4:52 am

What do you mean?
You mean my make.profile should link to amd64/2007.0/desktop or amd64/2007.0/server?

If I link to one of them, can my gcc get multilib support?

The current profile of mine is default since my gentoo was installed.
I had read the whole gentoo install handbook, I could not find some clues with the profile changing to desktop or server, so I left it along...

Would anybody else know and do this change after gentoo installed? Why I don't know.

broken_chaos · Post by **broken_chaos** » Sun Aug 12, 2007 5:40 am

I've always seen (-multilib) on all programs (that have it), and I've never had a problem. I think multilib being enabled is beyond whether the USE flag shows up as enabled or not.

And no, you don't have to use the desktop or server profiles - plain old 2007.0 just has less USE flags by default that desktop, no other differences. It works perfectly here, with multilib.

loftwyr · Post by **loftwyr** » Sun Aug 12, 2007 5:45 am

multilib is enabled by default for all AMD64 profiles except (no-multilib). It's masked off to prevent people from accidentally turning it off.

Dinini · Post by **Dinini** » Sun Aug 12, 2007 5:52 am

There is nothing "odd" about /usr/portage/profile/default-linux/amd64/2007.0, it is the initial profile that you get with a stage 3 installation. However desktop or server profiles tend to make life easier for new users since the most commonly recommended use flags for a working setup are already selected and so the installation handbook recommends changing to one of them.

Configuration for multilib has changed recently (well recent for me, the amd64 faq still reflects the older method). Multilib is now an enforced default for /usr/portage/profile/default-linux/amd64/*. You will see "(-multilib)" when emerging because it is no longer an option however you ARE building a multilib system. For example, type "gcc -v" and you will see that gcc was built with multilib ("--enable-multilib").

For completeness, at this time hardened profiles do not have multilib as the default so you would have to choose /usr/portage/profile/hardened/amd64/multilib and add "multilib" to your use flags to have a hardened multilib system.

ccgoo · Post by **ccgoo** » Sun Aug 12, 2007 3:53 pm

Dinini
Thank you.
Yes, I gcc -v and I found "--enable-multilib" there, I equery uses gcc and I found "-multilib" there too.

That is funny, why the developers use "(-multilib)" to represent multilib enabled?

Any way, I should ignore "(-multilib)" when I merge the packages, right?

Btw: I have another confusing, where is the change documented, the change of multilib is enforced to be enabled for default-linux/amd64? (how you found this?)
Thanks again.

ccgoo · Post by **ccgoo** » Sun Aug 12, 2007 4:35 pm

Dinini wrote: the amd64 faq still reflects the older method

yes yes yes, the amd64 faq does be too old to be helpful.

In that faq, it is still said that reiser4 is still not available for amd64 arch.

Where should we report issue like this -- doc is out of time?

Dinini · Post by **Dinini** » Mon Aug 13, 2007 7:48 am

ccgoo wrote:That is funny, why the developers use "(-multilib)" to represent multilib enabled?

The developers use (-multilib) to represent that the use flag is disabled. You would see the same thing if you were using the "no-multilib" profile (where multilib is disabled).

The same ebuilds are used for all profiles, some profiles do not select if multilib is used, for them (hardened/amd64 for example) the use flag is still required so the ebuild has to have the use flag.

ccgoo wrote:Any way, I should ignore "(-multilib)" when I merge the packages, right?

Yes, you should ignore it, it has no effect in your profile.

As far as having the change documented, I don't recall seeing a documentation notice. I did go reading through the profiles and saw the changes there.

The amd64 handbook no longer mentions the use flag and instead tells you to switch to a no-multilib profile to disable multilib. The english amd64 faq has been altered as well.

Requests for changes to gentoo.org documentation should be made using bugzilla. (Changes to gentoo-wiki documents should never be reported there as that is an independent site.)

ccgoo · Post by **ccgoo** » Mon Aug 13, 2007 9:37 am

OK， Dinini, thank you very much for your detailed reply. Of course, thanks the other people.

I really got it.

anomalizer · Post by **anomalizer** » Wed Aug 15, 2007 9:08 am

ccgoo wrote:Dinini
Yes, I gcc -v and I found "--enable-multilib" there, I equery uses gcc and I found "-multilib" there too. That is funny, why the developers use "(-multilib)" to represent multilib enabled?

I think so too. If a flag cannot be set/unset by the user, then I'd expect the forced state to show..in this case (multilib) and not (-multilib)