Re: [gentoo-user] how to upgrade perl

[Andrew Savchenko]

Hi,

On Mon, 20 Jun 2016 18:27:36 +0200 lee wrote:
> how do you do an update despite perl blocking it?
>
>
> emerge -a --update --newuse --deep --with-bdeps=y --keep-going @world
> [...]
> dev-lang/perl:0
>
>   (dev-lang/perl-5.22.2:0/5.22::gentoo, ebuild scheduled for merge) pulled in by
>     =dev-lang/perl-5.22* required by (virtual/perl-IO-Zlib-1.100.0-r6:0/0::gentoo, installed)
>     ^              ^^^^^
>     (and 8 more with the same problem)
>
>   (dev-lang/perl-5.20.2:0/5.20::gentoo, installed) pulled in by
>     dev-lang/perl:0/5.20=[-build(-)] required by (dev-perl/Encode-Locale-1.30.0-r1:0/0::gentoo, installed)
>                  ^^^^^^^^
>     =dev-lang/perl-5.20* required by (virtual/perl-Pod-Parser-1.620.0:0/0::gentoo, installed)
>     ^              ^^^^^
>     (and 56 more with the same problems)
> [...]

Your problem is likely not in perl itself, but in subslot deps
resolution. Looks like you have other unresolved dependencies, but
they can't be seen because of subslots. To solve this one needs to
temporary disable subslots, fix all issues, then enable subslots back.

First run emerge with subslots ignored:
  emerge -DNuav --with-bdeps=y --ignore-built-slot-operator-deps y --backtrack 10  @world 

After this command you will see other blockers than listed in your
mail. Fix them until the command above will build dep tree without
errors. Afterwards run your usual emerge command with subslots
enabled, e.g.:
  emerge -DNuav --with-bdeps=y --backtrack 10  @world 
and you should be fine.

See also bug 540562:
https://bugs.gentoo.org/show_bug.cgi?id=540562

This problem may be solved with huge backtrack value, but in my case
--backtrack=100 was not enough and 1000 was not possible to check,
because even 100 took about 3 hours(!!) to run.

Best regards,
Andrew Savchenko