Requested in https://github.com/systemd/systemd/pull/33214#discussion_r1630251308.
Also, reword error messages a bit. When /usr/lib/clock-epoch was introduced,
"build time" stopped being acurate. Just say "epoch" instead.
The same message ID is used in the manager and timesyncd. The event is
essentially equivalent for the user, and it seems reasonable that to search for
both at the same time.
The catalog entry is dropped. It provided almost no additional information above
the message. When the same message ID is now applied to messages from PID1 and
timesyncd, and the clock can be both advanced and rewound, it becomes very hard
to make the catalog entry provide something useful, because catalog entries don't
allow conditionalization.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Let's allow distros to change the support URL to expose in catalog entries by
default. It doesn't make sense to direct end-users to the upstream project for
common errors.
This adds a --with-support-url= switch to configure, which allows overriding
the default at build-time.
Fixes: #2516
