The `set -e` option is incompatible with a subshell/compound command,
which is followed by || <EXPR>. In such case, the -e option is ignored
in all affected subshells/functions (see man bash(1) for command `set`).
In certain cases we might attempt to install a binary which is already
present in the test image, yet it's missing from the host system.
In such cases, let's check if the binary indeed exists in the image
before doing any other chcecks. If it does, immediately return with
success.
This was discovered during installation of
/usr/lib/systemd/systemd-bless-boot, which was not present in Ubuntu CI
(as the installed systemd was from the Ubuntu repositories), and the
binary itself was already in the image thanks to `ninja install`.
However, during extraction of binaries from the systemd service files,
another attempt to install this binary was made, which failed due to
`find_binary` being unable to find it.
Before only one comparison was allowed. Let's make this more flexible:
ConditionKernelVersion = ">=4.0" "<=4.5"
Fixes#12881.
This also fixes expressions like "ConditionKernelVersion=>" which would
evaluate as true.
A class was used to put some utility functions under a namespace. But then this
namespace was inherited into classes, so the namespace split was undone. Let's
just define those functions in the module namespace.
(The Utilities class with a few functions still remain, because of the
unittest-style self.assert* craziness.)
For normal shell calls, python syntax is quite verbose. We don't need to punish
ourselves like that. In some places we would fork a shell to do argument splitting
for us. We know that our arguments can be safely split on whitespace, so let's do
that ourselves in all cases, without forking a shell.
We also expect command output to be valid text, so let's always set
universal_newlines=True.
This makes things shorter and easier to read. Development is also easier because
it's possible to paste many of the commands directly to/from a shell.
Adds the resumeflags= kernel command line option to allow setting a
custom device timeout for the resume device (defaults to the same as the
root device).
