Running: ./testmodel.py --libraries=/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/ --ompython_omhome=/usr Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4.conf.json
loadFile("/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Buildings 9.0.0-master/package.mo", uses=false)
loadFile("/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo", uses=false)
loadFile("/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo", uses=false)
loadFile("/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo", uses=false)
Using package ModelicaServices with version 4.0.0 (/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo)
Using package Modelica with version 4.0.0 (/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo)
Using package Complex with version 4.0.0 (/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo)
Using package Buildings with version 9.0.0 (/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Buildings 9.0.0-master/package.mo)
Running command: translateModel(Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4,tolerance=1e-06,outputFormat="empty",numberOfIntervals=172800,variableFilter="",fileNamePrefix="Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4")
translateModel(Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4,tolerance=1e-06,outputFormat="empty",numberOfIntervals=172800,variableFilter="",fileNamePrefix="Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4")
Notification: Performance of loadFile(/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Buildings 9.0.0-master/package.mo): time 1.576/1.576, allocations: 306.1 MB / 321.4 MB, free: 10.7 MB / 250.7 MB
Notification: Performance of loadFile(/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.0009901/0.0009902, allocations: 179.2 kB / 393.1 MB, free: 4.078 MB / 314.7 MB
Notification: Performance of loadFile(/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.252/1.252, allocations: 225.7 MB / 0.6743 GB, free: 12.5 MB / 0.4948 GB
Notification: Performance of loadFile(/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/converted-libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.0007908/0.0007909, allocations: 103.1 kB / 0.7935 GB, free: 40.15 MB / 0.5417 GB
Notification: Performance of FrontEnd - loaded program: time 0.0003077/0.0003077, allocations: 8 kB / 0.9224 GB, free: 8.656 MB / 0.6355 GB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.4958/0.4961, allocations: 121.3 MB / 1.041 GB, free: 58.95 MB / 0.698 GB
Notification: Performance of NFInst.instantiate(Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4): time 0.1335/0.6296, allocations: 144.9 MB / 1.182 GB, free: 1.113 MB / 0.7448 GB
Notification: Performance of NFInst.instExpressions: time 0.02611/0.6558, allocations: 23.44 MB / 1.205 GB, free: 10.68 MB / 0.7761 GB
Notification: Performance of NFInst.updateImplicitVariability: time 0.001946/0.6578, allocations: 43.69 kB / 1.205 GB, free: 10.64 MB / 0.7761 GB
Notification: Performance of NFTyping.typeComponents: time 0.001853/0.6597, allocations: 1.13 MB / 1.206 GB, free: 9.91 MB / 0.7761 GB
Notification: Performance of NFTyping.typeBindings: time 0.001794/0.6615, allocations: 0.8116 MB / 1.207 GB, free: 9.34 MB / 0.7761 GB
Notification: Performance of NFTyping.typeClassSections: time 0.00138/0.6629, allocations: 374.9 kB / 1.208 GB, free: 9.043 MB / 0.7761 GB
Notification: Performance of NFFlatten.flatten: time 0.002076/0.665, allocations: 1.342 MB / 1.209 GB, free: 7.914 MB / 0.7761 GB
Notification: Performance of NFFlatten.resolveConnections: time 0.001242/0.6662, allocations: 0.5895 MB / 1.209 GB, free: 7.469 MB / 0.7761 GB
Notification: Performance of NFEvalConstants.evaluate: time 0.001113/0.6673, allocations: 488.3 kB / 1.21 GB, free: 7.086 MB / 0.7761 GB
Notification: Performance of NFSimplifyModel.simplify: time 0.001409/0.6688, allocations: 0.8785 MB / 1.211 GB, free: 6.402 MB / 0.7761 GB
Notification: Performance of NFPackage.collectConstants: time 0.0001904/0.669, allocations: 28 kB / 1.211 GB, free: 6.375 MB / 0.7761 GB
Notification: Performance of NFFlatten.collectFunctions: time 0.0003981/0.6694, allocations: 70.75 kB / 1.211 GB, free: 6.309 MB / 0.7761 GB
Notification: Performance of NFScalarize.scalarize: time 0.0003693/0.6698, allocations: 287 kB / 1.211 GB, free: 6.094 MB / 0.7761 GB
Notification: Performance of NFVerifyModel.verify: time 0.000598/0.6704, allocations: 471 kB / 1.212 GB, free: 5.645 MB / 0.7761 GB
Notification: Performance of NFConvertDAE.convert: time 0.001427/0.6718, allocations: 1.127 MB / 1.213 GB, free: 4.922 MB / 0.7761 GB
Notification: Performance of FrontEnd - DAE generated: time 5.71e-06/0.6718, allocations: 0.5156 kB / 1.213 GB, free: 4.922 MB / 0.7761 GB
Notification: Performance of FrontEnd: time 1.593e-06/0.6718, allocations: 0 / 1.213 GB, free: 4.922 MB / 0.7761 GB
Notification: Performance of Transformations before backend: time 4.465e-05/0.6719, allocations: 0 / 1.213 GB, free: 4.922 MB / 0.7761 GB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 107
 * Number of variables: 107
Notification: Performance of Generate backend data structure: time 0.002583/0.6745, allocations: 1.323 MB / 1.214 GB, free: 3.676 MB / 0.7761 GB
Notification: Performance of prepare preOptimizeDAE: time 5.258e-05/0.6745, allocations: 8.828 kB / 1.214 GB, free: 3.668 MB / 0.7761 GB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.0003701/0.6749, allocations: 143.2 kB / 1.214 GB, free: 3.527 MB / 0.7761 GB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.001292/0.6762, allocations: 0.6523 MB / 1.215 GB, free: 2.824 MB / 0.7761 GB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.0001901/0.6764, allocations: 74.69 kB / 1.215 GB, free: 2.746 MB / 0.7761 GB
Notification: Performance of preOpt expandDerOperator (simulation): time 0.0001466/0.6766, allocations: 48 kB / 1.215 GB, free: 2.699 MB / 0.7761 GB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.001301/0.6779, allocations: 0.5262 MB / 1.215 GB, free: 2.156 MB / 0.7761 GB
Notification: Performance of preOpt findStateOrder (simulation): time 2.595e-05/0.6779, allocations: 4 kB / 1.215 GB, free: 2.152 MB / 0.7761 GB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 5.518e-05/0.678, allocations: 16 kB / 1.215 GB, free: 2.137 MB / 0.7761 GB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 1.365e-05/0.678, allocations: 8 kB / 1.215 GB, free: 2.129 MB / 0.7761 GB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.001078/0.6791, allocations: 431.6 kB / 1.216 GB, free: 1.707 MB / 0.7761 GB
Warning: The model contains alias variables with redundant start and/or conflicting nominal values. It is recommended to resolve the conflicts, because otherwise the system could be hard to solve. To print the conflicting alias sets and the chosen candidates please use -d=aliasConflicts.
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.004391/0.6835, allocations: 2.862 MB / 1.219 GB, free: 14.6 MB / 0.7917 GB
Notification: Performance of preOpt comSubExp (simulation): time 0.001032/0.6845, allocations: 473.7 kB / 1.219 GB, free: 14.13 MB / 0.7917 GB
Notification: Performance of preOpt resolveLoops (simulation): time 0.0005718/0.6851, allocations: 298.3 kB / 1.219 GB, free: 13.84 MB / 0.7917 GB
Notification: Performance of preOpt evalFunc (simulation): time 3.882e-05/0.6852, allocations: 4 kB / 1.219 GB, free: 13.83 MB / 0.7917 GB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 0.0005754/0.6857, allocations: 310.6 kB / 1.22 GB, free: 13.52 MB / 0.7917 GB
Notification: Performance of pre-optimization done (n=45): time 8.486e-06/0.6858, allocations: 3.984 kB / 1.22 GB, free: 13.52 MB / 0.7917 GB
Notification: Performance of matching and sorting (n=45): time 0.00284/0.6886, allocations: 1.273 MB / 1.221 GB, free: 12.19 MB / 0.7917 GB
Notification: Performance of inlineWhenForInitialization (initialization): time 4.568e-05/0.6887, allocations: 55.41 kB / 1.221 GB, free: 12.12 MB / 0.7917 GB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.001964/0.6906, allocations: 1.74 MB / 1.223 GB, free: 10.38 MB / 0.7917 GB
Notification: Performance of collectPreVariables (initialization): time 4.837e-05/0.6907, allocations: 37.7 kB / 1.223 GB, free: 10.33 MB / 0.7917 GB
Notification: Performance of collectInitialEqns (initialization): time 0.000421/0.6911, allocations: 0.5179 MB / 1.223 GB, free: 9.809 MB / 0.7917 GB
Notification: Performance of collectInitialBindings (initialization): time 0.0001334/0.6913, allocations: 153.9 kB / 1.223 GB, free: 9.656 MB / 0.7917 GB
Notification: Performance of simplifyInitialFunctions (initialization): time 2.561e-05/0.6913, allocations: 8 kB / 1.223 GB, free: 9.648 MB / 0.7917 GB
Notification: Performance of setup shared object (initialization): time 0.0001079/0.6914, allocations: 330 kB / 1.224 GB, free: 9.32 MB / 0.7917 GB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0004951/0.6919, allocations: 237 kB / 1.224 GB, free: 9.09 MB / 0.7917 GB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.0005276/0.6925, allocations: 341.7 kB / 1.224 GB, free: 8.719 MB / 0.7917 GB
Notification: Performance of analyzeInitialSystem (initialization): time 0.0009003/0.6934, allocations: 0.5273 MB / 1.225 GB, free: 8.156 MB / 0.7917 GB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 4.118e-06/0.6934, allocations: 0 / 1.225 GB, free: 8.156 MB / 0.7917 GB
Notification: Performance of matching and sorting (n=67) (initialization): time 0.001671/0.6951, allocations: 0.8912 MB / 1.226 GB, free: 7.254 MB / 0.7917 GB
Notification: Performance of prepare postOptimizeDAE: time 1.956e-05/0.6951, allocations: 7.906 kB / 1.226 GB, free: 7.246 MB / 0.7917 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 9.779e-06/0.6951, allocations: 4 kB / 1.226 GB, free: 7.242 MB / 0.7917 GB
Notification: Performance of postOpt tearingSystem (initialization): time 0.0005095/0.6956, allocations: 184.8 kB / 1.226 GB, free: 7.059 MB / 0.7917 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0003608/0.696, allocations: 107.8 kB / 1.226 GB, free: 6.953 MB / 0.7917 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.003229/0.6992, allocations: 2.73 MB / 1.229 GB, free: 4.094 MB / 0.7917 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0004912/0.6997, allocations: 91.55 kB / 1.229 GB, free: 4.004 MB / 0.7917 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 4.345e-05/0.6998, allocations: 20 kB / 1.229 GB, free: 3.984 MB / 0.7917 GB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 13
 * Number of states: 0 ()
 * Number of discrete variables: 19 ($PRE.assEqu.nFai,assEqu.nFai,$whenCondition5,$whenCondition4,$PRE.intGai.nextTimeEvent,$whenCondition3,$PRE.reference.nextTimeEvent,$whenCondition1,$whenCondition2,reference.nextTimeEvent,$PRE.reference.nextTimeEventScaled,reference.nextTimeEventScaled,$PRE.assEqu.satisfied,assEqu.satisfied,$PRE.mean.y_last,mean.y_last,intGai.nextTimeEvent,$PRE.intGai.nextTimeEventScaled,intGai.nextTimeEventScaled)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (50):
 * Single equations (assignments): 49
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 1
 * Mixed (continuous/discrete) equation systems: 0
Notification: Torn system details for strict tearing set:
 * Linear torn systems (#iteration vars, #inner vars, density): 1 system
   {(2,16,100.0%)}
 * Non-linear torn systems (#iteration vars, #inner vars): 0 systems
Notification: Performance of prepare postOptimizeDAE: time 0.0005573/0.7004, allocations: 387.3 kB / 1.229 GB, free: 3.598 MB / 0.7917 GB
Notification: Performance of postOpt lateInlineFunction (simulation): time 0.0001403/0.7005, allocations: 114.5 kB / 1.229 GB, free: 3.484 MB / 0.7917 GB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.0002381/0.7007, allocations: 143.5 kB / 1.229 GB, free: 3.336 MB / 0.7917 GB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 5.521e-06/0.7008, allocations: 8 kB / 1.229 GB, free: 3.328 MB / 0.7917 GB
Notification: Performance of postOpt constantLinearSystem (simulation): time 1.164e-05/0.7008, allocations: 0 / 1.229 GB, free: 3.328 MB / 0.7917 GB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 6.202e-06/0.7008, allocations: 3.984 kB / 1.229 GB, free: 3.324 MB / 0.7917 GB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.002491/0.7033, allocations: 1.589 MB / 1.231 GB, free: 1.676 MB / 0.7917 GB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 5.18e-06/0.7033, allocations: 4 kB / 1.231 GB, free: 1.672 MB / 0.7917 GB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0002269/0.7035, allocations: 51.95 kB / 1.231 GB, free: 1.621 MB / 0.7917 GB
Notification: Performance of postOpt tearingSystem (simulation): time 0.0004708/0.704, allocations: 191.6 kB / 1.231 GB, free: 1.43 MB / 0.7917 GB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 4.161e-05/0.7041, allocations: 19.98 kB / 1.231 GB, free: 1.41 MB / 0.7917 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 0.003885/0.708, allocations: 4.126 MB / 1.235 GB, free: 13.02 MB / 0.8073 GB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 1.222e-06/0.708, allocations: 0 / 1.235 GB, free: 13.02 MB / 0.8073 GB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.001802/0.7098, allocations: 1.088 MB / 1.236 GB, free: 11.91 MB / 0.8073 GB
Notification: Performance of postOpt removeConstants (simulation): time 0.0003005/0.7101, allocations: 219.5 kB / 1.236 GB, free: 11.68 MB / 0.8073 GB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.0001099/0.7102, allocations: 20 kB / 1.236 GB, free: 11.66 MB / 0.8073 GB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0003805/0.7106, allocations: 35.97 kB / 1.236 GB, free: 11.62 MB / 0.8073 GB
Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0001462/0.7108, allocations: 55.84 kB / 1.236 GB, free: 11.57 MB / 0.8073 GB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 4.132e-05/0.7108, allocations: 16 kB / 1.236 GB, free: 11.55 MB / 0.8073 GB
Notification: Performance of sorting global known variables: time 0.001453/0.7123, allocations: 1.273 MB / 1.238 GB, free: 10.27 MB / 0.8073 GB
Notification: Performance of sort global known variables: time 1.3e-07/0.7123, allocations: 0 / 1.238 GB, free: 10.27 MB / 0.8073 GB
Notification: Performance of remove unused functions: time 0.0008213/0.7131, allocations: 215.6 kB / 1.238 GB, free: 10.06 MB / 0.8073 GB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 1
 * Number of states: 4 (thermalZoneTwoElements.extWallRC.thermCapExt[1].T,thermalZoneTwoElements.intWallRC.thermCapInt[1].T,assEqu.diff,mean.x)
 * Number of discrete variables: 12 ($whenCondition5,$whenCondition4,$whenCondition3,$whenCondition2,$whenCondition1,intGai.nextTimeEvent,intGai.nextTimeEventScaled,reference.nextTimeEvent,reference.nextTimeEventScaled,assEqu.satisfied,assEqu.nFai,mean.y_last)
 * Number of discrete states: 7 (intGai.nextTimeEvent,reference.nextTimeEvent,mean.x,assEqu.satisfied,assEqu.nFai,reference.nextTimeEventScaled,intGai.nextTimeEventScaled)
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for simulation (28):
 * Single equations (assignments): 20
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 6
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 2
 * Mixed (continuous/discrete) equation systems: 0
Notification: Torn system details for strict tearing set:
 * Linear torn systems (#iteration vars, #inner vars, density): 2 systems
   {(2,13,100.0%), (1,3,100.0%)}
 * Non-linear torn systems (#iteration vars, #inner vars): 0 systems
Notification: Performance of Backend phase and start with SimCode phase: time 0.001061/0.7142, allocations: 0.5544 MB / 1.238 GB, free: 9.672 MB / 0.8073 GB
Notification: Performance of simCode: created initialization part: time 0.00152/0.7157, allocations: 0.7452 MB / 1.239 GB, free: 8.918 MB / 0.8073 GB
Notification: Performance of simCode: created event and clocks part: time 3.015e-06/0.7157, allocations: 0 / 1.239 GB, free: 8.918 MB / 0.8073 GB
Notification: Performance of simCode: created simulation system equations: time 0.0008581/0.7166, allocations: 0.5636 MB / 1.24 GB, free: 8.328 MB / 0.8073 GB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.0009688/0.7176, allocations: 184.5 kB / 1.24 GB, free: 8.148 MB / 0.8073 GB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.003591/0.7212, allocations: 2.76 MB / 1.243 GB, free: 5.359 MB / 0.8073 GB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0007423/0.7219, allocations: 1.153 MB / 1.244 GB, free: 4.18 MB / 0.8073 GB
Notification: Performance of simCode: alias equations: time 0.0002949/0.7222, allocations: 88.78 kB / 1.244 GB, free: 4.09 MB / 0.8073 GB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0001093/0.7224, allocations: 47.42 kB / 1.244 GB, free: 4.043 MB / 0.8073 GB
Notification: Performance of SimCode: time 1.964e-06/0.7224, allocations: 0 / 1.244 GB, free: 4.043 MB / 0.8073 GB
Notification: Performance of Templates: time 0.01834/0.7407, allocations: 9.625 MB / 1.253 GB, free: 10.54 MB / 0.823 GB
make -j1 -f Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4.makefile
(rm -f Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4.pipe ; mkfifo Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4.pipe ; head -c 1048576 < Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4.pipe >> ../files/Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4.sim & ./Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4 -abortSlowSimulation -alarm=480 -lv LOG_STATS > Buildings_latest_Buildings.ThermalZones.ReducedOrder.Validation.VDI6007.TestCase4.pipe 2>&1)