libsystemd-shared-252.so not found

[LiamFry]

Backup (rear -v mkbackup) reports that a necessary file is missing. I don't understand ...

• ReaR version: Relax-and-Recover 2.7 / Git
• OS version: Debian GNU/Linux 12 (bookworm)
• ReaR configuration files: (attached)
• System architecture: x86_64
• Storage layout: (attached)
• Description of the issue:
  I am not sure if this is a rear issue yet I cannot find any useful information elsewhere. (I've tried!) During backup, I get the following message ...

Testing that the recovery system in /var/tmp/rear.PvzABq2iZtXbVTm/rootfs contains a usable system
/usr/lib/x86_64-linux-gnu/systemd/libsystemd-core-252.so requires additional libraries
        libsystemd-shared-252.so => not found
ReaR recovery system in '/var/tmp/rear.PvzABq2iZtXbVTm/rootfs' needs additional libraries, check /var/log/rear/rear-clara.log for details

dpkg --get-selections | grep libsystemd-shared shows that it's installed.
dpkg -L libsystemd-shared gives me the following ...

/.
/usr
/usr/lib
/usr/lib/x86_64-linux-gnu
/usr/lib/x86_64-linux-gnu/systemd
/usr/lib/x86_64-linux-gnu/systemd/libsystemd-core-252.so
/usr/lib/x86_64-linux-gnu/systemd/libsystemd-shared-252.so
/usr/share
/usr/share/doc
/usr/share/doc/libsystemd-shared
/usr/share/doc/libsystemd-shared/NEWS.Debian.gz
/usr/share/doc/libsystemd-shared/changelog.Debian.gz
/usr/share/doc/libsystemd-shared/copyright
/usr/share/lintian
/usr/share/lintian/overrides
/usr/share/lintian/overrides/libsystemd-shared

All that said, a quick find / -name libsystemd-shared-252.so -ls reports this:

22458549 3252 -rw-r--r-- 1 root root 3327624 Feb 28 06:15 /usr/lib/x86_64-linux-gnu/systemd/libsystemd-shared-252.so

local.conf.txt
storage-layout.txt

[jsmeix]

I am not a Debian user
so I cannot reproduce Debian specific issues.

In general when things are missing in the ReaR recovery system
you could manually add what is needed via something like

LIBS+=( /usr/lib/x86_64-linux-gnu/systemd/libsystemd-shared-252.so )

or

LIBS+=( /usr/lib/x86_64-linux-gnu/systemd/*.so* )

in your etc/rear/local.conf file.

See the descriptions about LIBS and COPY_AS_IS
in usr/share/rear/conf/default.conf

[pcahyna]

I see a similar message on Fedora 37:

Testing that the recovery system in /tmp/rear.OBGH5kwM9RvJv5S/rootfs contains a usable system
There are binaries or libraries in the ReaR recovery system that need additional libraries
/usr/lib/systemd/libsystemd-core-251.14-2.fc37.so requires additional libraries
libsystemd-shared-251.14-2.fc37.so => not found

Weird.

[LiamFry]

A quick run of ldd /usr/lib/x86_64-linux-gnu/systemd/libsystemd-core-252.so did report that libsystemd-shared-252.so was missing. This is damned odd.
I took my question to the Debian forums. I'll post here what I discover.

[pcahyna]

Similar on Fedora 37:

# ldd /usr/lib/systemd/libsystemd-core-251.14-2.fc37.so 
        linux-vdso.so.1 (0x00007ffefb5d6000)
        libsystemd-shared-251.14-2.fc37.so => not found

libsystemd-shared-251.14-2.fc37.so is actually in /usr/lib/systemd .

[jsmeix]

I guess that the RequiredSharedObjects function in ReaR
does not get called for libsystemd-core-252.so
so libsystemd-shared-252.so is not automatically
included into the ReaR recovery system.

RequiredSharedObjects is called in
build/GNU/Linux/390_copy_binaries_libraries.sh
for all existing programs in PROGS and REQUIRED_PROGS
and for all libraries in LIBS via

local all_libs=( "${LIBS[@]}" $( RequiredSharedObjects "${all_binaries[@]}" "${LIBS[@]}" ) )

and RequiredSharedObjects is called in
build/GNU/Linux/100_copy_as_is.sh
for all executable files in COPY_AS_IS via

for required_library in $( RequiredSharedObjects "${copy_as_is_executables[@]}" ) ; do

So when libsystemd-core-252.so is not specified in LIBS
but gets included into the recovery system via COPY_AS_IS
and when libsystemd-core-252.so is not an executable file
then RequiredSharedObjects is not called for libsystemd-core-252.so
so libsystemd-shared-252.so gets not automatically included
and when libsystemd-shared-252.so is not explicitly
specified to be included into the recovery system
then libsystemd-shared-252.so is missing in the recovery system.

[jsmeix]

@pcahyna
Ah!
It seems the library configuration on the original system
(i.e. things like ldconfig and so on)
could be incomplete when ldd does not find it.

[jsmeix]

FYI:

On my current openSUSE Leap 15.4 system
I have systemd-249.16 which contains only
/usr/lib/systemd/libsystemd-shared-249.so
and I noticed no issues with that in ReaR.

After "rear -D mkrescue" I get:

# find /var/tmp/rear.Dw2DUk0fyAfXiN6/rootfs | grep libsystemd

/var/tmp/rear.Dw2DUk0fyAfXiN6/rootfs/usr/lib64/libsystemd.so.0
/var/tmp/rear.Dw2DUk0fyAfXiN6/rootfs/usr/lib64/libsystemd.so.0.32.0
/var/tmp/rear.Dw2DUk0fyAfXiN6/rootfs/usr/lib/systemd/libsystemd-shared-249.so

and my var/log/rear/rear-HOSTNAME.log contains

+ source /root/rear.github.master/usr/share/rear/build/GNU/Linux/100_copy_as_is.sh
...
++ Log 'Adding required libraries of executables in all the copied files to LIBS'
...
2023-06-27 13:23:44.707937689 Adding required library '/usr/lib/systemd/libsystemd-shared-249.so' to LIBS
...
2023-06-27 13:23:45.113024540 Adding required library '/usr/lib64/libsystemd.so.0' to LIBS
.
.
.
+ source /root/rear.github.master/usr/share/rear/build/GNU/Linux/390_copy_binaries_libraries.sh
...
2023-06-27 13:23:53.056375594 Libraries being copied: ... /usr/lib/systemd/libsystemd-shared-249.so ... /usr/lib64/libsystemd.so.0 ...

As far as I see in particular in
usr/share/rear/prep/GNU/Linux/280_include_systemd.sh
and in usr/share/rear/conf/GNU/Linux.conf
it seems that
libsystemd-shared-249.so and libsystemd.so.0
are not specified in LIBS
but get included into the recovery system
via executables in COPY_AS_IS or
via programs in PROGS and REQUIRED_PROGS
which should normally be the preferred way
according to my reasoning in
#2743

[LiamFry]

I found this post that offered some "solutions." Even though the question was asked for Ubuntu, I found it helpful for Debian.

TL;DR

One-off solution:

sudo bash -c "LD_PRELOAD=/usr/lib/x86_64-linux-gnu/systemd/libsystemd-shared-252.so" rear -v mkbackup
(untested)

... OR ...

create an file in /etc/ld.so.conf.d
(This is the method I chose.)

I created /etc/ld.so.conf.d/libsystemd-core.conf
... into which I put /usr/lib/x86_64-linux-gnu/systemd
I then ran sudo ldconf

A run of ldd /usr/lib/x86_64-linux-gnu/systemd/libsystemd-core-252.so now resolves libsystemd-shared-252.so

I rebooted for good measure and ran a straight rear -v mkbackup -- it ran flawlessly.

I suppose why libsystemd-core-252.so has this issue is a question for the distro and subsystem teams.

[ekool]

I just want to add that the above post from LiamFry fixed it for me as well.

[sid-the-sloth]

sudo ldconf

This solution from @LiamFry worked -- but on Debian should do sudo ldconfig instead.