There is a problem with SIGCHLD signal handling in
vixie-cron version 3.0.1, releases 19 through 24, on
Red Hat Linux 5.0 & 5.1. This can cause problems with
cron jobs that are run from bash, which doesn't reset
the signal action to SIG_DFL when it's set to SIG_IGN.
Programs that expect normal SIGCHLD handling can fail
in cron jobs. An example is programs that use popen(),
and check the result of pclose() - it fails with ECHILD.
The htmerge program in ht://Dig fails quite consistently
when run from a cron job on 5.0 or 5.1.
This bug is fixed in vixie-cron-3.0.1-26.src.rpm, in
Red Hat 5.2. However, no mention is made of this in
the errata for 5.0 and 5.1, and no update RPMs have
been issued for these systems. This is a frequent source
of confusion and frustration for Red Hat 5.0 and 5.1 users.