Re: [RFC] Overhaul Autotest's logging

[Akim Demaille]

 >> > mismatch between expected stderr and observed stderr because
 >> > of shell traces

 Bonzini> Note that my patch does not even attempt to do this.  I don't think
 Bonzini> it can be easily done, at least I don't know enough shell magic to
 Bonzini> achieve it.

Then you probably have inherited the bit of dubious magic that was
already implemented:

# Any line of stderr starting with leading blanks and a `+' are filtered
# out, since most shells when tracing include subshell traces in stderr.
# This may cause spurious failures when the test suite is run with `-x'.

...
m4_define([AT_CHECK],
[$at_traceoff
$at_verbose "AT_LINE: AS_ESCAPE([$1])"
echo AT_LINE >$at_check_line_file
( $at_traceon; $1 ) >$at_stdout 2>$at_stder1
at_status=$?
grep '^ *+' $at_stder1 >&2                   <=======
grep -v '^ *+' $at_stder1 >$at_stderr        <=======


 Bonzini> Applied.  Also updated NEWS to warn about the possible failures
 Bonzini> when -x is used together with experr.

Thanks!  Testing asap.