Execution Chart

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

Trace from the execution

Formatting '/mnt/tpsp/fkordon/mcc2023-input.r446-tajo-167905989000114.qcow2', fmt=qcow2 size=4294967296 backing_file='/mnt/tpsp/fkordon/mcc2023-input.qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
Waiting for the VM to be ready (probing ssh)
.......................
=====================================================================
Generated by BenchKit 2-5348
Executing tool gold2022
Input is ShieldRVs-PT-050A, examination is ReachabilityFireability
Time confinement is 3600 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r446-tajo-167905989000114
=====================================================================

--------------------
preparation of the directory to be used:
/home/mcc/execution
total 744K
-rw-r--r-- 1 mcc users 6.7K Feb 26 18:44 CTLCardinality.txt
-rw-r--r-- 1 mcc users 73K Feb 26 18:44 CTLCardinality.xml
-rw-r--r-- 1 mcc users 5.8K Feb 26 18:31 CTLFireability.txt
-rw-r--r-- 1 mcc users 54K Feb 26 18:31 CTLFireability.xml
-rw-r--r-- 1 mcc users 6 Mar 5 18:23 equiv_col
-rw-r--r-- 1 mcc users 4.2K Jan 29 11:41 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 6.5K Jan 29 11:41 GenericPropertiesVerdict.xml
-rw-r--r-- 1 mcc users 5 Mar 5 18:23 instance
-rw-r--r-- 1 mcc users 6 Mar 5 18:23 iscolored
-rw-r--r-- 1 mcc users 3.8K Feb 25 17:03 LTLCardinality.txt
-rw-r--r-- 1 mcc users 29K Feb 25 17:03 LTLCardinality.xml
-rw-r--r-- 1 mcc users 2.3K Feb 25 17:03 LTLFireability.txt
-rw-r--r-- 1 mcc users 19K Feb 25 17:03 LTLFireability.xml
-rw-r--r-- 1 mcc users 320K Mar 5 18:23 model.pnml
-rw-r--r-- 1 mcc users 8.3K Feb 26 19:05 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 81K Feb 26 19:05 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 8.1K Feb 26 18:52 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 69K Feb 26 18:52 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 1.6K Feb 25 17:03 UpperBounds.txt
-rw-r--r-- 1 mcc users 3.7K Feb 25 17:03 UpperBounds.xml

--------------------
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 ShieldRVs-PT-050A-ReachabilityFireability-00
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-01
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-02
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-03
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-04
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-05
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-06
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-07
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-08
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-09
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-10
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-11
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-12
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-13
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-14
FORMULA_NAME ShieldRVs-PT-050A-ReachabilityFireability-15

=== Now, execution of the tool begins

BK_START 1679447633980

gold2022
Got BK_BIN_PATH=/home/mcc/BenchKit/bin/
---> gold2022 --- TAPAAL v5
Setting MODEL_PATH=.
Setting VERIFYPN=/home/mcc/BenchKit/bin/verifypn
Got BK_TIME_CONFINEMENT=3600
Setting TEMPDIR=/home/mcc/BenchKit/bin/tmp
Got BK_MEMORY_CONFINEMENT=16384
Limiting to 16265216 kB
Total timeout: 3590
Time left: 3590

**********************************************
* TAPAAL verifying ReachabilityFireability *
**********************************************
TEMPDIR=/home/mcc/BenchKit/bin/tmp
QF=/home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN
MF=/home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL
Time left: 3590
---------------------------------------------------
Step -1: Stripping Colors
---------------------------------------------------
Verifying stripped models (16 in total)
/home/mcc/BenchKit/bin/verifypn -n -c -q 718 -l 29 -d 299 -z 4 -x 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 ./model.pnml ./ReachabilityFireability.xml
CPN OverApproximation is only usable on colored models
Time left: 3590
---------------------------------------------------
Step 0: Parallel Simplification
---------------------------------------------------
Doing parallel simplification (16 in total)
Total simplification timout is 718 -- reduction timeout is 299
timeout 3590 /home/mcc/BenchKit/bin/verifypn -n -q 718 -l 29 -d 299 -z 4 -s OverApprox --binary-query-io 2 --write-simplified /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --write-reduced /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL -x 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 ./model.pnml ./ReachabilityFireability.xml

Time left: 3502

---------------------------------------------------
Step 1: Parallel processing
---------------------------------------------------
Doing parallel verification of individual queries (16 in total)
Each query is verified by 4 parallel strategies for 256 seconds
------------------- QUERY 1 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.002074 on verification
@@@0.04,8860@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ BestFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 1 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-02 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3502
------------------- QUERY 2 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.018071 on verification
@@@0.08,8988@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 2 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-09 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3501
------------------- QUERY 3 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.0222 on verification
@@@0.09,8868@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 3 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-07 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3501
------------------- QUERY 4 ----------------------
Solution found by parallel processing (step 1)
Search strategy option was ignored as the TAR engine is called.
Query index 0 was solved

Query is NOT satisfied.


Solved using Trace Abstraction Refinement

Spent 192.475 on verification
@@@192.52,18980@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -tar\ -s\ RDFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 4 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-14 FALSE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT TRACE_ABSTRACTION_REFINEMENT
Time left: 3308
------------------- QUERY 5 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.912954 on verification
@@@0.96,17872@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 5 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-01 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3307
------------------- QUERY 6 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is NOT satisfied.

Spent 0.004928 on verification
@@@0.08,8876@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 6 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-12 FALSE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3306
------------------- QUERY 7 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.038385 on verification
@@@0.07,8960@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ BestFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 7 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-00 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3306
------------------- QUERY 8 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.028485 on verification
@@@0.09,8964@@@
Query index 0 was solved

Query is satisfied.

Spent 0.019297 on verification
@@@0.08,8988@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 8 -n
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ BestFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 8 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-10 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3306
------------------- QUERY 9 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is NOT satisfied.

Spent 0.003427 on verification
@@@0.05,8888@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ BestFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 9 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-08 FALSE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3305
------------------- QUERY 10 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.007275 on verification
@@@0.05,8964@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 10 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-05 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3305
------------------- QUERY 11 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.012922 on verification
@@@0.06,9068@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 11 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-03 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3305
------------------- QUERY 12 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.275719 on verification
@@@0.33,8896@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ BFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 12 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-11 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3304
------------------- QUERY 13 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.023941 on verification
@@@0.06,9028@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ DFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 13 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-13 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3304
------------------- QUERY 14 ----------------------
No solution found



Time left: 3045
------------------- QUERY 15 ----------------------
Solution found by parallel processing (step 1)
Query index 0 was solved

Query is satisfied.

Spent 0.014553 on verification
@@@0.06,8944@@@
parallel: This job succeeded:
eval /usr/bin/time -f "@@@%e,%M@@@" /home/mcc/BenchKit/bin/verifypn -n -s\ BestFS\ -q\ 0\ -l\ 0\ -d\ 119 /home/mcc/BenchKit/bin/tmp/tmp.ghFSsZLluL /home/mcc/BenchKit/bin/tmp/tmp.slGzpcY6SN --binary-query-io 1 -x 15 -n

FORMULA ShieldRVs-PT-050A-ReachabilityFireability-04 TRUE TECHNIQUES COLLATERAL_PROCESSING STRUCTURAL_REDUCTION QUERY_REDUCTION SAT_SMT EXPLICIT STATE_COMPRESSION STUBBORN_SETS
Time left: 3044
------------------- QUERY 16 ----------------------
No solution found



Time left: 2785
---------------------------------------------------
Step 2: Sequential processing
---------------------------------------------------
Remaining 2 queries are verified sequentially.
Each query is verified for a dynamic timeout (at least 598 seconds)
Time left: 2785
------------------- QUERY 14 ----------------------
Running query 14 for 1392 seconds. Remaining: 2 queries and 2785 seconds
No solution found



Time left: 1390
------------------- QUERY 16 ----------------------
Running query 16 for 1390 seconds. Remaining: 1 queries and 1390 seconds
No solution found



Time left: -2
Out of time, terminating!
terminated-with-cleanup

BK_STOP 1679451226720

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

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="ShieldRVs-PT-050A"
export BK_EXAMINATION="ReachabilityFireability"
export BK_TOOL="gold2022"
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 2-5348"
echo " Executing tool gold2022"
echo " Input is ShieldRVs-PT-050A, examination is ReachabilityFireability"
echo " Time confinement is $BK_TIME_CONFINEMENT seconds"
echo " Memory confinement is 16384 MBytes"
echo " Number of cores is 4"
echo " Run identifier is r446-tajo-167905989000114"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"

tar xzf /home/mcc/BenchKit/INPUTS/ShieldRVs-PT-050A.tgz
mv ShieldRVs-PT-050A execution
cd execution
if [ "ReachabilityFireability" = "ReachabilityDeadlock" ] || [ "ReachabilityFireability" = "UpperBounds" ] || [ "ReachabilityFireability" = "QuasiLiveness" ] || [ "ReachabilityFireability" = "StableMarking" ] || [ "ReachabilityFireability" = "Liveness" ] || [ "ReachabilityFireability" = "OneSafe" ] || [ "ReachabilityFireability" = "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 [ "ReachabilityFireability" = "UpperBounds" ] ; then
echo "The expected result is a vector of positive values"
echo NUM_VECTOR
elif [ "ReachabilityFireability" != "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 "ReachabilityFireability.txt" ] ; then
echo "here is the order used to build the result vector(from text file)"
for x in $(grep Property ReachabilityFireability.txt | cut -d ' ' -f 2 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ -f "ReachabilityFireability.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 '' ReachabilityFireability.xml | cut -d '>' -f 2 | cut -d '<' -f 1 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ "ReachabilityFireability" = "ReachabilityDeadlock" ] || [ "ReachabilityFireability" = "QuasiLiveness" ] || [ "ReachabilityFireability" = "StableMarking" ] || [ "ReachabilityFireability" = "Liveness" ] || [ "ReachabilityFireability" = "OneSafe" ] ; then
echo "FORMULA_NAME ReachabilityFireability"
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 ;