Bug#1061248: glibc: DEP17: move most files but rtld to /usr

[Sven Joachim <svenjoac@gmx.de>]

Am 21.01.2024 um 15:25 schrieb Helmut Grohne:

> Source: glibc
> Version: 2.37-13
> Tags: patch
> User: helmutg@debian.org
> Usertags: dep17m2
>
> Hi Aurelien,
>
> thanks for your answers on IRC to my design question. As promised here
> comes a patch that moves most files in binary packages built from glibc
> from aliased locations to /usr. This excludes the runtime dynamic linker
> for native libc packages (i.e. not multilib), because moving it would
> break filesystem bootstrap unless base-files installs the aliasing
> symlinks at the same time.

I have not studied the details, but this looks rather dangerous to me.
If you install the runtime dynamic linker in multilib packages below
/usr, but keep the native one at its current place, you risk losing it
when the multilib packages are removed.

For instance, I have both libc6:i386 and libc6-i386:amd64 installed.  If
the latter starts shipping /usr/lib/ld-linux.so.2 rather than
/lib/ld-linux.so.2, the "Replaces" in libc6:i386 becomes ineffective,
and we have basically a case of Dep17 P1.

True, there is already a file loss problem today.  If I were to remove
libc6:i386 now, I would be left without /lib/ld-linux.so.2 as well.  But
in such a situation it is always possible to remedy the situation by
reinstalling libc6-i386.  This is not ensured if only libc6-i386 is
removed, as essential programs might depend on libc6:i386, leaving no
easy way of recovery.

Cheers,
       Sven