Hi Laurent, I'm pretty sure some change in skalibs v2.3.6.0 broke some types of message handling in ucspilogd. Specifically, a computer I have running skalibs v2.3.5.1 and s6 v2.1.6.0 is able to read messages sent via the logger command, whereas a computer I have running skalibs v2.3.6.0 and s6 v2.2.0.0 cannot.
ucspilogd v2.2.0.0 gives the following when I send a message via logger: root@radon:~# logger woo @4000000055c6fe44103957dc ucspilogd: fatal: unable to read from stdin: Broken pipe ucspilogd v2.1.6.0: root@heliocat:~# logger woo @4000000055c6fe7401034cdc 0: 0: user.notice: Aug 9 07:16:32 heliocat: woo I initially thought it was in the handoff code between s6-ipcserverd and ucspilogd but after stracing the s6-ipcserverd process and following forked off children, I'm pretty sure the issue is in ucspilogd (or, more correctly, the skalibs functions that ucspilogd wraps since the main program hasn't changed in months). I haven't yet dug into the skalibs code to see what changed between those tags, or started bisecting it to find out which commit broke. However, the difference between a functional and non-functional log write in strace is the following: Functional: [pid 19388] readv(0, [{"<13>Aug 9 07:26:07 cathexis: wo"..., 8191}, {NULL, 0}], 2) = 34 [pid 19388] writev(1, [{"1000: 1000: user.notice: Aug 9 "..., 55}, {NULL, 0}], 2) = 55 [pid 19388] readv(0, [{"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8158}, {"<13>Aug 9 07:26:07 cathexis: wo"..., 33}], 2) = 0 Dysfunctional: [pid 31983] readv(0, [{"<13>Aug 8 23:46:57 cathexis: wo"..., 8191}, {NULL, 0}], 2) = 33 [pid 31983] readv(0, [{"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8159}, {"<13>Aug 8 23:46:57 cathexis: wo", 32}], 2) = 0 [pid 31983] writev(2, [{"ucspilogd: fatal: unable to read"..., 57}, {NULL, 0}], 2) = 57 Some syslog messages generated via non-logger sources work, such as auth messages. Those have the same readv, writev, readv pattern. Let me know if you need more. Cheers! -- "If the doors of perception were cleansed every thing would appear to man as it is, infinite. For man has closed himself up, till he sees all things thru' narrow chinks of his cavern." -- William Blake