This reverts commit 491b736a49.
If the _static_ linked version of busybox is installed, openSUSE doesn't need
any specific code.
A following commit will make sure that the static linked version of busybox is
installed in the busybox container.
machinectl fails since 21935150a0 as it's now
mounting onto a file descriptor in a target namespace, without joining the
target's PID namespace.
Note that it's not enough to setns CLONE_NEWPID, but a double-fork is required
as well, as implemented by namespace_fork().
Add a test case to TEST-13-NSPAWN to cover this use case.
We have four legal cases:
1. /usr/lib/os-release exists and /etc/os-release is a symlink to it
2. both exist but /etc/os-release is not a symlink to /usr/lib/os-release
3. only /usr/lib/os-release exists
4. only /etc/os-release exists
The generic setup code in test-functions and create-busybox-image didn't handle
case 3.
The test-specific code in TEST-50 didn't handle 2 (because the general setup
code would only install /etc/os-release in the image and
grep -f /usr/lib/os-release would not work) and 4 (same reason) and would fail
in case 3 in generic setup.
