[gentoo-dev] [RFC] amd64 17.1 profiles stable

[Aaron Bauman]

Good day, all.

Following up on Michał's work with the amd64 17.1 profiles, I have
revised the original news item for review with the intent of moving the
profiles to stable.

These profiles were initially published by Michał in December 2017 as
exp and were moved to dev status in December 2018. As such, these profiles
will now be marked stable following the news item review.

===

Title: amd64 17.1 Profiles
Author: Michał Górny <mgorny@g.o>
Posted: 2019-12-23
Revision: 4
News-Item-Format: 2.0
Display-If-Profile: default/linux/amd64/13.0
Display-If-Profile: default/linux/amd64/13.0/selinux
Display-If-Profile: default/linux/amd64/13.0/desktop
Display-If-Profile: default/linux/amd64/13.0/desktop/gnome
Display-If-Profile: default/linux/amd64/13.0/desktop/gnome/systemd
Display-If-Profile: default/linux/amd64/13.0/desktop/plasma
Display-If-Profile: default/linux/amd64/13.0/desktop/plasma/systemd
Display-If-Profile: default/linux/amd64/13.0/developer
Display-If-Profile: default/linux/amd64/13.0/no-multilib
Display-If-Profile: default/linux/amd64/13.0/systemd
Display-If-Profile: default/linux/amd64/17.0
Display-If-Profile: default/linux/amd64/17.0/selinux
Display-If-Profile: default/linux/amd64/17.0/hardened
Display-If-Profile: default/linux/amd64/17.0/hardened/selinux
Display-If-Profile: default/linux/amd64/17.0/desktop
Display-If-Profile: default/linux/amd64/17.0/desktop/gnome
Display-If-Profile: default/linux/amd64/17.0/desktop/gnome/systemd
Display-If-Profile: default/linux/amd64/17.0/desktop/plasma
Display-If-Profile: default/linux/amd64/17.0/desktop/plasma/systemd
Display-If-Profile: default/linux/amd64/17.0/developer
Display-If-Profile: default/linux/amd64/17.0/no-multilib
Display-If-Profile: default/linux/amd64/17.0/no-multilib/hardened
Display-If-Profile: default/linux/amd64/17.0/no-multilib/hardened/selinux
Display-If-Profile: default/linux/amd64/17.0/systemd

The 17.1 amd64 profiles have been in the Gentoo repository for several months
and have been tested in exp and dev profile statuses. These profiles switch to
a more standard 'no SYMLINK_LIB' multilib layout, and require explicit migration
as described below. They are now considered stable.

In these profiles, the lib->lib64 compatibility symlink is removed.
The 'lib' directory becomes a separate directory, that is used
for cross-arch and native non-library packages (gcc, clang) and 32-bit
libraries on the multilib profile (for better compatibility with
prebuilt x86 packages).

Migration from both 13.0 and 17.0 profiles are supported. In case
of the former, please read the news item for 17.0 upgrade first
and enable gcc 6.4.0 or newer first as explained there.

The migration is performed using app-portage/unsymlink-lib tool.
The following steps can be used to upgrade your system:

1. Sync and upgrade your system to the newest package versions
   to reduce the risk of issues.

2. Install the tool, e.g. via 'emerge -1v app-portage/unsymlink-lib'

3. Run 'unsymlink-lib --analyze' and check the output for obvious
   mistakes. If you need to perform any changes to the system, remember
   to run 'unsymlink-lib --analyze' again afterwards.

[past this point do not call emerge or modify /usr manually]

4. This is a very good time to make a backup.

5. Run 'unsymlink-lib --migrate'. You can add '--pretend' first to see
   what is going to happen.

6. Reboot your system and see if it still boots. Check if important
   programs work. In particular, check if e.g. 'emerge --info' works
   (but do not install anything). If you hit any serious problems,
   you can use 'unsymlink-lib --rollback' to revert the changes
   and return to step 3.

7. Run 'unsymlink-lib --finish'. You can add '--pretend' first to see
   what is going to happen but note that you're going to see a very long
   list of files to remove.

8. Switch the profile, e.g.:

     eselect profile set --force default/linux/amd64/17.1/desktop

[at this point you can start using emerge again]

9. Rebuild sys-devel/gcc. If you are switching from 13.0 profiles,
   rebuild sys-devel/binutils and sys-libs/glibc afterwards.

10. If you are using a multilib profile, rebuild all 32-bit packages.
    This can be done using:

      emerge -1v /lib32 /usr/lib32

    Alternatively, if you are switching from one of the 13.0 profiles
    you can rebuild all packages as detailed in the 17.0 news item.

11. Once the last 32-bit package is rebuilt, your package manager
    should remove the orphaned /lib32 and /usr/lib32 symlinks. If that
    does not happen, remove them manually.

For known issues, please see bug #506276 [1]. If you have any problems
with the new profiles or the migration procedure, please report a bug
and make it block the tracker.

For more information on the layout, please see the wiki article
on AMD64 multilib layouts [2].

[1]:https://bugs.gentoo.org/506276
[2]:https://wiki.gentoo.org/wiki/Project:AMD64/Multilib_layout


-- 
Cheers,
Aaron