Execution Chart

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

Trace from the execution

Formatting '/data/fkordon/mcc2024-input.r399-tall-171690530700602.qcow2', fmt=qcow2 size=4294967296 backing_file=/data/fkordon/mcc2024-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 2-5568
Executing tool greatspnxred
Input is Sudoku-PT-AN05, examination is CTLFireability
Time confinement is 3600 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r399-tall-171690530700602
=====================================================================

--------------------
preparation of the directory to be used:
/home/mcc/execution
total 2.9M
-rw-r--r-- 1 mcc users 46K Apr 12 11:35 CTLCardinality.txt
-rw-r--r-- 1 mcc users 251K Apr 12 11:35 CTLCardinality.xml
-rw-r--r-- 1 mcc users 94K Apr 12 11:31 CTLFireability.txt
-rw-r--r-- 1 mcc users 473K Apr 12 11:31 CTLFireability.xml
-rw-r--r-- 1 mcc users 4.2K May 18 16:43 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 6.6K May 18 16:43 GenericPropertiesVerdict.xml
-rw-r--r-- 1 mcc users 38K Apr 23 08:00 LTLCardinality.txt
-rw-r--r-- 1 mcc users 141K Apr 23 08:00 LTLCardinality.xml
-rw-r--r-- 1 mcc users 59K Apr 23 08:00 LTLFireability.txt
-rw-r--r-- 1 mcc users 224K Apr 23 08:00 LTLFireability.xml
-rw-r--r-- 1 mcc users 48K Apr 12 11:41 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 288K Apr 12 11:41 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 193K Apr 12 11:37 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 931K Apr 12 11:37 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 4.0K Apr 23 08:00 UpperBounds.txt
-rw-r--r-- 1 mcc users 9.9K Apr 23 08:00 UpperBounds.xml
-rw-r--r-- 1 mcc users 5 May 18 16:43 equiv_col
-rw-r--r-- 1 mcc users 5 May 18 16:43 instance
-rw-r--r-- 1 mcc users 6 May 18 16:43 iscolored
-rw-r--r-- 1 mcc users 80K May 18 16:43 model.pnml

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

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

The expected result is a vector of booleans
BOOL_VECTOR

here is the order used to build the result vector(from text file)
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-00
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-01
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-02
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-03
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-04
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-05
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-06
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-07
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-08
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-09
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-10
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-11
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-12
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-13
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-14
FORMULA_NAME Sudoku-PT-AN05-CTLFireability-2024-15

=== Now, execution of the tool begins

BK_START 1717057568132

Invoking MCC driver with
BK_TOOL=greatspnxred
BK_EXAMINATION=CTLFireability
BK_BIN_PATH=/home/mcc/BenchKit/bin/
BK_TIME_CONFINEMENT=3600
BK_INPUT=Sudoku-PT-AN05
BK_MEMORY_CONFINEMENT=16384
Applying reductions before tool greatspn
Invoking reducer
Running Version 202405141337
[2024-05-30 08:26:09] [INFO ] Running its-tools with arguments : [-pnfolder, /home/mcc/execution, -examination, CTLFireability, -timeout, 360, -rebuildPNML]
[2024-05-30 08:26:09] [INFO ] Parsing pnml file : /home/mcc/execution/model.pnml
[2024-05-30 08:26:09] [INFO ] Load time of PNML (sax parser for PT used): 77 ms
[2024-05-30 08:26:09] [INFO ] Transformed 200 places.
[2024-05-30 08:26:09] [INFO ] Transformed 125 transitions.
[2024-05-30 08:26:09] [INFO ] Found NUPN structural information;
[2024-05-30 08:26:09] [INFO ] Parsed PT model containing 200 places and 125 transitions and 500 arcs in 173 ms.
Parsed 16 properties from file /home/mcc/execution/CTLFireability.xml in 38 ms.
FORMULA Sudoku-PT-AN05-CTLFireability-2024-02 TRUE TECHNIQUES TOPOLOGICAL INITIAL_STATE
Support contains 75 out of 200 places. Attempting structural reductions.
Starting structural reductions in LTL mode, iteration 0 : 200/200 places, 125/125 transitions.
Reduce places removed 125 places and 0 transitions.
Iterating post reduction 0 with 125 rules applied. Total rules applied 125 place count 75 transition count 125
Applied a total of 125 rules in 19 ms. Remains 75 /200 variables (removed 125) and now considering 125/125 (removed 0) transitions.
// Phase 1: matrix 125 rows 75 cols
[2024-05-30 08:26:09] [INFO ] Computed 14 invariants in 17 ms
[2024-05-30 08:26:09] [INFO ] Implicit Places using invariants in 181 ms returned []
[2024-05-30 08:26:09] [INFO ] Invariant cache hit.
[2024-05-30 08:26:10] [INFO ] Implicit Places using invariants and state equation in 110 ms returned []
Implicit Place search using SMT with State Equation took 320 ms to find 0 implicit places.
Running 0 sub problems to find dead transitions.
Search for dead transitions found 0 dead transitions in 2ms
Starting structural reductions in LTL mode, iteration 1 : 75/200 places, 125/125 transitions.
Finished structural reductions in LTL mode , in 1 iterations and 360 ms. Remains : 75/200 places, 125/125 transitions.
Support contains 75 out of 75 places after structural reductions.
[2024-05-30 08:26:10] [INFO ] Flatten gal took : 80 ms
[2024-05-30 08:26:10] [INFO ] Flatten gal took : 65 ms
[2024-05-30 08:26:11] [INFO ] Input system was already deterministic with 125 transitions.
Reduction of identical properties reduced properties to check from 48 to 42
RANDOM walk for 40000 steps (1820 resets) in 1727 ms. (23 steps per ms) remains 1/42 properties
BEST_FIRST walk for 40004 steps (48 resets) in 2068 ms. (19 steps per ms) remains 1/1 properties
[2024-05-30 08:26:12] [INFO ] Invariant cache hit.
Problem AtomicPropp5 is UNSAT
After SMT solving in domain Real declared 75/200 variables, and 0 constraints, problems are : Problem set: 1 solved, 0 unsolved in 57 ms.
Refiners :[Domain max(s): 0/75 constraints, Generalized P Invariants (flows): 0/14 constraints, State Equation: 0/75 constraints, PredecessorRefiner: 1/1 constraints, Known Traps: 0/0 constraints]
After SMT, in 346ms problems are : Problem set: 1 solved, 0 unsolved
Skipping Parikh replay, no witness traces provided.
Successfully simplified 1 atomic propositions for a total of 15 simplifications.
[2024-05-30 08:26:12] [INFO ] Flatten gal took : 39 ms
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 40 ms
[2024-05-30 08:26:13] [INFO ] Input system was already deterministic with 125 transitions.
Computed a total of 75 stabilizing places and 125 stable transitions
Complete graph has no SCC; deadlocks are unavoidable. place count 75 transition count 125
Detected that all paths lead to deadlock. Applying this knowledge to assert that all AP eventually converge (and all enablings converge to false).
AF dead knowledge conclusive for 1 formulas.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 1 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 12 ms
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 17 ms
[2024-05-30 08:26:13] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 1 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 11 ms
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 15 ms
[2024-05-30 08:26:13] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in SI_CTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 4 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in SI_CTL mode , in 1 iterations and 4 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 9 ms
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 8 ms
[2024-05-30 08:26:13] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 1 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:13] [INFO ] Flatten gal took : 9 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 12 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 1 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 8 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 11 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in SI_CTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in SI_CTL mode , in 1 iterations and 2 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 9 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 7 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 0 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 0 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 9 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 11 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 6 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 6 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 6 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 4 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 4 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 4 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 5 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 5 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in SI_CTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 5 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in SI_CTL mode , in 1 iterations and 5 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 4 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 4 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 8 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 1 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 4 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 1 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 4 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
Starting structural reductions in LTL mode, iteration 0 : 75/75 places, 125/125 transitions.
Applied a total of 0 rules in 1 ms. Remains 75 /75 variables (removed 0) and now considering 125/125 (removed 0) transitions.
Finished structural reductions in LTL mode , in 1 iterations and 1 ms. Remains : 75/75 places, 125/125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 5 ms
[2024-05-30 08:26:14] [INFO ] Input system was already deterministic with 125 transitions.
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 41 ms
[2024-05-30 08:26:14] [INFO ] Flatten gal took : 39 ms
[2024-05-30 08:26:15] [INFO ] Export to MCC of 15 properties in file /home/mcc/execution/CTLFireability.sr.xml took 49 ms.
[2024-05-30 08:26:15] [INFO ] Export to PNML in file /home/mcc/execution/model.sr.pnml of net with 75 places, 125 transitions and 375 arcs took 4 ms.
Total runtime 5903 ms.
There are residual formulas that ITS could not solve within timeout
----------------------------------------------------------------------
GreatSPN-meddly tool, MCC 2023
----------------------------------------------------------------------

Running Sudoku-PT-AN05

IS_COLORED=
IS_NUPN=

LOADING PETRI NET FILE /home/mcc/execution/405/model.pnml (PNML) ...
PNML VERSION 2009, P/T NET.
COLOR CLASSES: 0
CONSTANTS: 0
PLACES: 75
TRANSITIONS: 125
COLOR VARS: 0
MEASURES: 0
LOADING TIME: [User 0.001s, Sys 0.003s]


SAVING FILE /home/mcc/execution/405/model (.net / .def) ...
EXPORT TIME: [User 0.000s, Sys 0.000s]


----------------------------------------------------------------------
GreatSPN/Meddly.
Copyright (C) 1987-2022, University of Torino, Italy.
website: https://github.com/greatspn/SOURCES

Based on MEDDLY version 0.16.0
Copyright (C) 2009, Iowa State University Research Foundation, Inc.
website: http://meddly.sourceforge.net

Process ID: 534
MODEL NAME: /home/mcc/execution/405/model
75 places, 125 transitions.

Creating all event NSFs..
Creating all event NSFs..
Creating all event NSFs..
Creating all event NSFs..
Split: SplitSubtract
Start RS construction.
Split: SplitSubtract
Start RS construction.
Split: SplitSubtract
Start RS construction.
Split: SplitSubtract
Start RS construction.

BK_TIME_CONFINEMENT_REACHED

--------------------
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//
++ ls /home/mcc/BenchKit/bin//../reducer/bin//../../itstools//itstools/plugins/fr.lip6.move.gal.application.pnmcc_1.0.0.202405141337.jar
++ perl -pe 's/.*\.//g'
+ VERSION=202405141337
+ echo 'Running Version 202405141337'
+ /home/mcc/BenchKit/bin//../reducer/bin//../../itstools//itstools/its-tools -pnfolder /home/mcc/execution -examination CTLFireability -timeout 360 -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="Sudoku-PT-AN05"
export BK_EXAMINATION="CTLFireability"
export BK_TOOL="greatspnxred"
export BK_RESULT_DIR="/tmp/BK_RESULTS/OUTPUTS"
export BK_TIME_CONFINEMENT="3600"
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 2-5568"
echo " Executing tool greatspnxred"
echo " Input is Sudoku-PT-AN05, examination is CTLFireability"
echo " Time confinement is $BK_TIME_CONFINEMENT seconds"
echo " Memory confinement is 16384 MBytes"
echo " Number of cores is 4"
echo " Run identifier is r399-tall-171690530700602"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"

tar xzf /home/mcc/BenchKit/INPUTS/Sudoku-PT-AN05.tgz
mv Sudoku-PT-AN05 execution
cd execution
if [ "CTLFireability" = "ReachabilityDeadlock" ] || [ "CTLFireability" = "UpperBounds" ] || [ "CTLFireability" = "QuasiLiveness" ] || [ "CTLFireability" = "StableMarking" ] || [ "CTLFireability" = "Liveness" ] || [ "CTLFireability" = "OneSafe" ] || [ "CTLFireability" = "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 [ "CTLFireability" = "UpperBounds" ] ; then
echo "The expected result is a vector of positive values"
echo NUM_VECTOR
elif [ "CTLFireability" != "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 "CTLFireability.txt" ] ; then
echo "here is the order used to build the result vector(from text file)"
for x in $(grep Property CTLFireability.txt | cut -d ' ' -f 2 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ -f "CTLFireability.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 '' CTLFireability.xml | cut -d '>' -f 2 | cut -d '<' -f 1 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ "CTLFireability" = "ReachabilityDeadlock" ] || [ "CTLFireability" = "QuasiLiveness" ] || [ "CTLFireability" = "StableMarking" ] || [ "CTLFireability" = "Liveness" ] || [ "CTLFireability" = "OneSafe" ] ; then
echo "FORMULA_NAME CTLFireability"
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 ;