On 5/10/19 3:12 PM, Pierre Labastie via lfs-dev wrote:
On 10/05/2019 14:33, Douglas R. Reno via lfs-dev wrote:
On 5/10/19 2:21 AM, Pierre Labastie via lfs-dev wrote:
Hi,
I now build the systemd book. I may come back to SysV later, but ATM, I want
to test the BLFS book, and the systemd revision has more thorough coverage
than SysV.
Since i'm new to systemd, I try various commands. That's how I realized there
was a unit (man-db.timer) for running a daily update of the man database. So I
enabled the unit, and after one day, I received an error concerning the
associated service.
Investigating, it turns out that /usr/bin/find is hardcoded in the unit, and
we have find in /bin...
I wonder how many units have such harcoded paths.
Looking at man-db source, /usr/bin/find is hardcoded also in
man-db.service.in. So the following sed is needed:
sed -i 's@/usr/bin/find@/bin/find@' init/systemd/man-db.service.in
Should we add it to the systemd book?
Pierre
I've got that sed in my sandbox already, but I think it would be good to go in
now.
Please add it :-)
Not many units are supposed to have hardcoded paths. I don't know if this is
related to some upstreams' initiative to push for a merged / and /usr (where
/lib and /usr/lib are symlinked, /bin and /usr/bin are symlinked, etc). If it
is, it's a very nasty way to do things. Hardcoded paths are rarely a
requirement.
Hmm, the unit comes from man-db, and was added in last December, to fix a bug
in Debian. I do not think that debian is pushing for merging / and /usr. So,
no nasty way, just an oversight, I think...
As of whether it is possible to use the system PATH, I cannot tell. Somebody
with better systemd knowledge than I have should answer: sure it'd be better,
but only if we can assess that the PATH is set when running the service...
Another possibility, as suggested, would be to symlink to /usr all the
executables we move from /usr/{s,}bin to /{s,}bin (as we do for libraries).
Symlinks are a possibility, but I would prefer not doing that if we
can. Note the that library symlinks are only to the .so files that are
used by build instructions. These are almost always symlinks anyway.
The actual libraries are not like libattr.so.1.1.2448 which are not
symlinked directly. The runtime loader automatically looks in /lib.
I note that our BLFS service files all seem to be using absolute file
paths so PATH may not be an option.
sed -i /find/s|/usr|| init/systemd/man-db.service.in
Note that this still will work in a merged /usr/bin = /bin system.
-- Bruce
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