Execution Chart

We display below the execution chart for this examination (boot time has been removed).

Trace from the execution

Formatting '/data/fkordon/mcc2025-input.r224-tall-174902009700178.qcow2', fmt=qcow2 size=4294967296 backing_file=/data/fkordon/mcc2025-input.qcow2 backing_fmt=qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16
Waiting for the VM to be ready (probing ssh)
............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
=====================================================================
Generated by BenchKit 2-5832
Executing tool gold2024
Input is ShieldRVt-PT-020B, examination is StableMarking
Time confinement is 1800 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r224-tall-174902009700178
=====================================================================

--------------------
preparation of the directory to be used:
/home/mcc/execution
total 680K
-rw-r--r-- 1 mcc users 8.8K May 29 14:47 CTLCardinality.txt
-rw-r--r-- 1 mcc users 103K May 29 14:47 CTLCardinality.xml
-rw-r--r-- 1 mcc users 4.5K May 29 14:47 CTLFireability.txt
-rw-r--r-- 1 mcc users 37K May 29 14:47 CTLFireability.xml
-rw-r--r-- 1 mcc users 4.2K May 29 14:33 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 3.7K May 29 14:47 LTLCardinality.txt
-rw-r--r-- 1 mcc users 26K May 29 14:47 LTLCardinality.xml
-rw-r--r-- 1 mcc users 2.3K May 29 14:47 LTLFireability.txt
-rw-r--r-- 1 mcc users 19K May 29 14:47 LTLFireability.xml
-rw-r--r-- 1 mcc users 11K May 29 14:47 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 110K May 29 14:47 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 7.4K May 29 14:47 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 60K May 29 14:47 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 1.6K May 29 14:47 UpperBounds.txt
-rw-r--r-- 1 mcc users 3.7K May 29 14:47 UpperBounds.xml
-rw-r--r-- 1 mcc users 6 May 29 14:33 equiv_col
-rw-r--r-- 1 mcc users 5 May 29 14:33 instance
-rw-r--r-- 1 mcc users 6 May 29 14:33 iscolored
-rw-r--r-- 1 mcc users 239K May 29 14:33 model.pnml

--------------------
content from stdout:

=== Data for post analysis generated by BenchKit (invocation template)

The expected result is a vector of booleans
BOOL_VECTOR

FORMULA_NAME StableMarking

=== Now, execution of the tool begins

BK_START 1749106699232

Invoking MCC driver with
BK_TOOL=gold2024
BK_EXAMINATION=StableMarking
BK_BIN_PATH=/home/mcc/BenchKit/bin/
BK_TIME_CONFINEMENT=1800
BK_INPUT=ShieldRVt-PT-020B
BK_MEMORY_CONFINEMENT=16384
Applying reductions before tool greatspn
Invoking reducer
Running Version 202405141337
[2025-06-05 06:58:20] [INFO ] Running its-tools with arguments : [-pnfolder, /home/mcc/execution, -examination, StableMarking, -timeout, 180, -rebuildPNML]
[2025-06-05 06:58:20] [INFO ] Parsing pnml file : /home/mcc/execution/model.pnml
[2025-06-05 06:58:20] [INFO ] Load time of PNML (sax parser for PT used): 105 ms
[2025-06-05 06:58:20] [INFO ] Transformed 1003 places.
[2025-06-05 06:58:20] [INFO ] Transformed 1003 transitions.
[2025-06-05 06:58:20] [INFO ] Found NUPN structural information;
[2025-06-05 06:58:20] [INFO ] Parsed PT model containing 1003 places and 1003 transitions and 2366 arcs in 222 ms.
Structural test allowed to assert that 401 places are NOT stable. Took 11 ms.
RANDOM walk for 40000 steps (8 resets) in 2276 ms. (17 steps per ms) remains 230/602 properties
BEST_FIRST walk for 403 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 6 ms. (57 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 10 ms. (36 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 10 ms. (36 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 22 ms. (17 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 19 ms. (20 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 11 ms. (33 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 16 ms. (23 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 10 ms. (36 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 14 ms. (26 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 10 ms. (36 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 21 ms. (18 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 11 ms. (33 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 12 ms. (31 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 10 ms. (36 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 10 ms. (36 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 6 ms. (57 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 7 ms. (50 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 6 ms. (57 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 7 ms. (50 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 6 ms. (57 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 7 ms. (50 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 6 ms. (57 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 7 ms. (50 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 10 ms. (36 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 7 ms. (50 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 9 ms. (40 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 7 ms. (50 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 402 steps (8 resets) in 6 ms. (57 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 6 ms. (57 steps per ms) remains 230/230 properties
BEST_FIRST walk for 403 steps (8 resets) in 8 ms. (44 steps per ms) remains 230/230 properties
BEST_FIRST walk for 404 steps (8 resets) in 5 ms. (67 steps per ms) remains 230/230 properties
// Phase 1: matrix 1003 rows 1003 cols
[2025-06-05 06:58:21] [INFO ] Computed 81 invariants in 27 ms
All remaining problems are real, not stopping.
At refinement iteration 0 (INCLUDED_ONLY) 0/230 variables, 230/230 constraints. Problems are: Problem set: 0 solved, 230 unsolved
At refinement iteration 1 (INCLUDED_ONLY) 0/230 variables, 0/230 constraints. Problems are: Problem set: 0 solved, 230 unsolved
At refinement iteration 2 (OVERLAPS) 277/507 variables, 40/270 constraints. Problems are: Problem set: 0 solved, 230 unsolved
At refinement iteration 3 (INCLUDED_ONLY) 0/507 variables, 277/547 constraints. Problems are: Problem set: 0 solved, 230 unsolved
Solver is answering 'unknown', stopping.
After SMT solving in domain Real declared 507/2006 variables, and 547 constraints, problems are : Problem set: 0 solved, 230 unsolved in 5283 ms.
Refiners :[Domain max(s): 507/1003 constraints, Positive P Invariants (semi-flows): 40/81 constraints, State Equation: 0/1003 constraints, PredecessorRefiner: 230/230 constraints, Known Traps: 0/0 constraints]
Escalating to Integer solving :Problem set: 0 solved, 230 unsolved
At refinement iteration 0 (INCLUDED_ONLY) 0/230 variables, 230/230 constraints. Problems are: Problem set: 0 solved, 230 unsolved
At refinement iteration 1 (INCLUDED_ONLY) 0/230 variables, 0/230 constraints. Problems are: Problem set: 0 solved, 230 unsolved
At refinement iteration 2 (OVERLAPS) 277/507 variables, 40/270 constraints. Problems are: Problem set: 0 solved, 230 unsolved
At refinement iteration 3 (INCLUDED_ONLY) 0/507 variables, 277/547 constraints. Problems are: Problem set: 0 solved, 230 unsolved
[2025-06-05 06:58:28] [INFO ] Deduced a trap composed of 60 places in 187 ms of which 29 ms to minimize.
[2025-06-05 06:58:28] [INFO ] Deduced a trap composed of 68 places in 153 ms of which 4 ms to minimize.
[2025-06-05 06:58:28] [INFO ] Deduced a trap composed of 74 places in 131 ms of which 3 ms to minimize.
[2025-06-05 06:58:28] [INFO ] Deduced a trap composed of 76 places in 132 ms of which 3 ms to minimize.
[2025-06-05 06:58:29] [INFO ] Deduced a trap composed of 38 places in 77 ms of which 2 ms to minimize.
[2025-06-05 06:58:29] [INFO ] Deduced a trap composed of 34 places in 76 ms of which 1 ms to minimize.
[2025-06-05 06:58:29] [INFO ] Deduced a trap composed of 38 places in 77 ms of which 2 ms to minimize.
[2025-06-05 06:58:29] [INFO ] Deduced a trap composed of 34 places in 73 ms of which 2 ms to minimize.
[2025-06-05 06:58:29] [INFO ] Deduced a trap composed of 47 places in 86 ms of which 2 ms to minimize.
[2025-06-05 06:58:30] [INFO ] Deduced a trap composed of 53 places in 83 ms of which 2 ms to minimize.
[2025-06-05 06:58:30] [INFO ] Deduced a trap composed of 44 places in 46 ms of which 1 ms to minimize.
[2025-06-05 06:58:30] [INFO ] Deduced a trap composed of 65 places in 80 ms of which 2 ms to minimize.
[2025-06-05 06:58:30] [INFO ] Deduced a trap composed of 48 places in 80 ms of which 2 ms to minimize.
[2025-06-05 06:58:30] [INFO ] Deduced a trap composed of 48 places in 84 ms of which 2 ms to minimize.
[2025-06-05 06:58:30] [INFO ] Deduced a trap composed of 74 places in 83 ms of which 2 ms to minimize.
[2025-06-05 06:58:30] [INFO ] Deduced a trap composed of 40 places in 93 ms of which 2 ms to minimize.
[2025-06-05 06:58:31] [INFO ] Deduced a trap composed of 55 places in 95 ms of which 2 ms to minimize.
[2025-06-05 06:58:31] [INFO ] Deduced a trap composed of 58 places in 95 ms of which 2 ms to minimize.
[2025-06-05 06:58:31] [INFO ] Deduced a trap composed of 58 places in 90 ms of which 2 ms to minimize.
[2025-06-05 06:58:31] [INFO ] Deduced a trap composed of 51 places in 90 ms of which 2 ms to minimize.
At refinement iteration 4 (INCLUDED_ONLY) 0/507 variables, 20/567 constraints. Problems are: Problem set: 0 solved, 230 unsolved
[2025-06-05 06:58:31] [INFO ] Deduced a trap composed of 75 places in 119 ms of which 2 ms to minimize.
[2025-06-05 06:58:31] [INFO ] Deduced a trap composed of 66 places in 120 ms of which 3 ms to minimize.
[2025-06-05 06:58:32] [INFO ] Deduced a trap composed of 40 places in 60 ms of which 1 ms to minimize.
Solver is answering 'unknown', stopping.
After SMT solving in domain Int declared 507/2006 variables, and 570 constraints, problems are : Problem set: 0 solved, 230 unsolved in 5009 ms.
Refiners :[Domain max(s): 507/1003 constraints, Positive P Invariants (semi-flows): 40/81 constraints, State Equation: 0/1003 constraints, PredecessorRefiner: 0/230 constraints, Known Traps: 23/23 constraints]
After SMT, in 10434ms problems are : Problem set: 0 solved, 230 unsolved
Skipping Parikh replay, no witness traces provided.
Support contains 230 out of 1003 places. Attempting structural reductions.
Starting structural reductions in REACHABILITY mode, iteration 0 : 1003/1003 places, 1003/1003 transitions.
Drop transitions (Trivial Post-Agglo cleanup.) removed 260 transitions
Trivial Post-agglo rules discarded 260 transitions
Performed 260 trivial Post agglomeration. Transition count delta: 260
Iterating post reduction 0 with 260 rules applied. Total rules applied 260 place count 1003 transition count 743
Reduce places removed 260 places and 0 transitions.
Ensure Unique test removed 1 transitions
Reduce isomorphic transitions removed 1 transitions.
Drop transitions (Trivial Post-Agglo cleanup.) removed 1 transitions
Trivial Post-agglo rules discarded 1 transitions
Performed 1 trivial Post agglomeration. Transition count delta: 1
Iterating post reduction 1 with 262 rules applied. Total rules applied 522 place count 743 transition count 741
Reduce places removed 1 places and 0 transitions.
Iterating post reduction 2 with 1 rules applied. Total rules applied 523 place count 742 transition count 741
Performed 53 Pre agglomeration using Quasi-Persistent + Divergent Free condition..
Pre-agglomeration after 3 with 53 Pre rules applied. Total rules applied 523 place count 742 transition count 688
Deduced a syphon composed of 53 places in 1 ms
Reduce places removed 53 places and 0 transitions.
Iterating global reduction 3 with 106 rules applied. Total rules applied 629 place count 689 transition count 688
Discarding 79 places :
Symmetric choice reduction at 3 with 79 rule applications. Total rules 708 place count 610 transition count 609
Iterating global reduction 3 with 79 rules applied. Total rules applied 787 place count 610 transition count 609
Performed 31 Pre agglomeration using Quasi-Persistent + Divergent Free condition..
Pre-agglomeration after 3 with 31 Pre rules applied. Total rules applied 787 place count 610 transition count 578
Deduced a syphon composed of 31 places in 2 ms
Reduce places removed 31 places and 0 transitions.
Iterating global reduction 3 with 62 rules applied. Total rules applied 849 place count 579 transition count 578
Performed 179 Post agglomeration using F-continuation condition.Transition count delta: 179
Deduced a syphon composed of 179 places in 2 ms
Reduce places removed 179 places and 0 transitions.
Iterating global reduction 3 with 358 rules applied. Total rules applied 1207 place count 400 transition count 399
Renaming transitions due to excessive name length > 1024 char.
Performed 33 Post agglomeration using F-continuation condition.Transition count delta: -28
Deduced a syphon composed of 33 places in 0 ms
Reduce places removed 33 places and 0 transitions.
Iterating global reduction 3 with 66 rules applied. Total rules applied 1273 place count 367 transition count 427
Drop transitions (Empty/Sink Transition effects.) removed 1 transitions
Reduce isomorphic transitions removed 1 transitions.
Iterating post reduction 3 with 1 rules applied. Total rules applied 1274 place count 367 transition count 426
Free-agglomeration rule applied 3 times.
Iterating global reduction 4 with 3 rules applied. Total rules applied 1277 place count 367 transition count 423
Reduce places removed 3 places and 0 transitions.
Iterating post reduction 4 with 3 rules applied. Total rules applied 1280 place count 364 transition count 423
Drop transitions (Redundant composition of simpler transitions.) removed 1 transitions
Redundant transition composition rules discarded 1 transitions
Iterating global reduction 5 with 1 rules applied. Total rules applied 1281 place count 364 transition count 422
Partial Free-agglomeration rule applied 1 times.
Drop transitions (Partial Free agglomeration) removed 1 transitions
Iterating global reduction 5 with 1 rules applied. Total rules applied 1282 place count 364 transition count 422
Reduce places removed 1 places and 1 transitions.
Iterating global reduction 5 with 1 rules applied. Total rules applied 1283 place count 363 transition count 421
Reduce places removed 1 places and 0 transitions.
Iterating post reduction 5 with 1 rules applied. Total rules applied 1284 place count 362 transition count 421
Applied a total of 1284 rules in 193 ms. Remains 362 /1003 variables (removed 641) and now considering 421/1003 (removed 582) transitions.
Finished structural reductions in REACHABILITY mode , in 1 iterations and 202 ms. Remains : 362/1003 places, 421/1003 transitions.
RANDOM walk for 670982 steps (168 resets) in 6234 ms. (107 steps per ms) remains 0/230 properties
Able to resolve query StableMarking after proving 603 properties.
FORMULA StableMarking FALSE TECHNIQUES RANDOM_WALK MARKED_SUFFIX_TEST TOPOLOGICAL
Total runtime 14821 ms.
ITS solved all properties within timeout

BK_STOP 1749106715313

--------------------
content from stderr:

+ ulimit -s 65536
+ [[ -z '' ]]
+ export LTSMIN_MEM_SIZE=8589934592
+ LTSMIN_MEM_SIZE=8589934592
+ export PYTHONPATH=/home/mcc/BenchKit/itstools/pylibs
+ PYTHONPATH=/home/mcc/BenchKit/itstools/pylibs
+ export LD_LIBRARY_PATH=/home/mcc/BenchKit/itstools/pylibs:
+ LD_LIBRARY_PATH=/home/mcc/BenchKit/itstools/pylibs:
++ sed s/.jar//
++ perl -pe 's/.*\.//g'
++ ls /home/mcc/BenchKit/bin//../reducer/bin//../../itstools//itstools/plugins/fr.lip6.move.gal.application.pnmcc_1.0.0.202405141337.jar
+ VERSION=202405141337
+ echo 'Running Version 202405141337'
+ /home/mcc/BenchKit/bin//../reducer/bin//../../itstools//itstools/its-tools -pnfolder /home/mcc/execution -examination StableMarking -timeout 180 -rebuildPNML

Sequence of Actions to be Executed by the VM

This is useful if one wants to reexecute the tool in the VM from the submitted image disk.

set -x
# this is for BenchKit: configuration of major elements for the test
export BK_INPUT="ShieldRVt-PT-020B"
export BK_EXAMINATION="StableMarking"
export BK_TOOL="gold2024"
export BK_RESULT_DIR="/tmp/BK_RESULTS/OUTPUTS"
export BK_TIME_CONFINEMENT="1800"
export BK_MEMORY_CONFINEMENT="16384"
export BK_BIN_PATH="/home/mcc/BenchKit/bin/"

# this is specific to your benchmark or test

export BIN_DIR="$HOME/BenchKit/bin"

# remove the execution directoty if it exists (to avoid increse of .vmdk images)
if [ -d execution ] ; then
rm -rf execution
fi

# this is for BenchKit: explicit launching of the test
echo "====================================================================="
echo " Generated by BenchKit 2-5832"
echo " Executing tool gold2024"
echo " Input is ShieldRVt-PT-020B, examination is StableMarking"
echo " Time confinement is $BK_TIME_CONFINEMENT seconds"
echo " Memory confinement is 16384 MBytes"
echo " Number of cores is 4"
echo " Run identifier is r224-tall-174902009700178"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"

tar xzf /home/mcc/BenchKit/INPUTS/ShieldRVt-PT-020B.tgz
mv ShieldRVt-PT-020B execution
cd execution
if [ "StableMarking" = "ReachabilityDeadlock" ] || [ "StableMarking" = "UpperBounds" ] || [ "StableMarking" = "QuasiLiveness" ] || [ "StableMarking" = "StableMarking" ] || [ "StableMarking" = "Liveness" ] || [ "StableMarking" = "OneSafe" ] || [ "StableMarking" = "StateSpace" ]; then
rm -f GenericPropertiesVerdict.xml
fi
pwd
ls -lh

echo
echo "--------------------"
echo "content from stdout:"
echo
echo "=== Data for post analysis generated by BenchKit (invocation template)"
echo
if [ "StableMarking" = "UpperBounds" ] ; then
echo "The expected result is a vector of positive values"
echo NUM_VECTOR
elif [ "StableMarking" != "StateSpace" ] ; then
echo "The expected result is a vector of booleans"
echo BOOL_VECTOR
else
echo "no data necessary for post analysis"
fi
echo
if [ -f "StableMarking.xml" ] ; then # for cunf (txt files deleted;-)
echo echo "here is the order used to build the result vector(from xml file)"
for x in $(grep '' StableMarking.xml | cut -d '>' -f 2 | cut -d '<' -f 1 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ "StableMarking" = "ReachabilityDeadlock" ] || [ "StableMarking" = "QuasiLiveness" ] || [ "StableMarking" = "StableMarking" ] || [ "StableMarking" = "Liveness" ] || [ "StableMarking" = "OneSafe" ] ; then
echo "FORMULA_NAME StableMarking"
fi
echo
echo "=== Now, execution of the tool begins"
echo
echo -n "BK_START "
date -u +%s%3N
echo
timeout -s 9 $BK_TIME_CONFINEMENT bash -c "/home/mcc/BenchKit/BenchKit_head.sh 2> STDERR ; echo ; echo -n \"BK_STOP \" ; date -u +%s%3N"
if [ $? -eq 137 ] ; then
echo
echo "BK_TIME_CONFINEMENT_REACHED"
fi
echo
echo "--------------------"
echo "content from stderr:"
echo
cat STDERR ;