WARNING: libcap needs an update (cap=40 should have a name)

[bdutta]

What is the reason that we get this warning message:

$ capsh --print
WARNING: libcap needs an update (cap=40 should have a name).
Current: =
Bounding set =cap_chown…

[Fritz]

The anticipated behaviour on ‘20.04’ using the ‘–print’ argument would be exacly what you are getting (I suppose), but without the warning text. The actual ‘libpcap’ library provided by Debian/Ubuntu/Lubuntu at this time is of the 1.x branch, and capabilties 38, 39 and 40 not are recognized, only after version 2.60.

Remains strange that you get the warning. Perhaps it is sufficient to ‘just’ pull your system to the latest software:

$ sudo apt update; sudo apt upgrade

Perhaps it helps to get rid of the warning text.

If the same problem remains, can you provide the following details?

$ cat /etc/issue
$ dpkg -l | grep libcap

[FeminalPanda]

I am getting tis as well even after upgrading.

cat /etc/issue
Ubuntu 20.04.4 LTS \n \l

dpkg -l | grep libcap

ii  libcap-ng0:amd64                                            0.7.9-2.1build1                               amd64        An alternate POSIX capabilities library 
ii  libcap2:amd64                                               1:2.32-1                                      amd64        POSIX 1003.1e capabilities (library)    
ii  libcap2-bin                                                 1:2.32-1                                      amd64        POSIX 1003.1e capabilities (utilities

[Fritz]

@FeminalPanda Thank your for your information. As I understood the initial remark by bdutta, he/she was wondering (or complaining) about the warning-text “WARNING: libcap needs an update (cap=40 should have a name).” That was weird indeed, since my 20.04.4 LTS system did as well not show caps 38, 39 and 40, but did not complain about that fact (just showed the numbers).

Unfortunately, I deleted the old 20.04 VM I have been using for testing and fiddling, and forgot about the exact value of 1.x (as it seemed not important at that time).

Now I have a VM 22.04 LTS running, and found out, after reading your post, that It shows the name instead of a number for e.g. capability 40 (cap_checkpoint_restore).

My conclusion is that 22.04 LTS is running newer versions of the 1.x libraries which recognise the missing caps. My versions on 22.04 of the libraries are 0.7.9.2.2build3 and 1.2.44-1build3 respectively.

So, the 1.x-branch has been updated (and not upgraded to 2.60+) in the upcoming Lubuntu 22.04 LTS distribution. Its libcap libraries have been backported from the 2.60+ version(s), to accomodate some newer capabilities (which were added to the 2.60+ branch in 2020, I think).

Hope this helps you.