Hi Guix,

Running 'make check' in the guix source tree on a CentOS 7 system
results in 15 FAILS:

tests/containers.log: 9 FAILS
tests/syscalls.log: 3 FAILS
tests/guix-environment-container.log: 1 FAIL
tests/guix-pack.log: 1 FAIL
tests/pack.log: 1 FAIL

Referring to bug#24108, the cause may be that the clone-related tests
are being executed instead of being skipped. 

The output of 'uname -srv' is:

Linux 3.10.0-862.3.3.el7.x86_64 #1 SMP Fri Jun 15 04:15:27 UTC 2018

Files:
a)  '/proc/self/ns/user' exists
b) '/proc/sys/kernel/unprivileged_userns_clone' does not exist.

On CentOS 7 I believe user namespaces are supported but disabled by
default.  The output of 'cat /proc/sys/user/max_user_namespaces' is
'0'.

Perhaps the 'perform-container-tests?' logic should include an extra
check for the default, disabled case to ensure that the tests are
skipped.

Attached are the log files, except 'guix-pack.log' (~100MB) and
'pack.log' (~7MB).

Best regards,

Paul.