Log file: https://cmssdt.cern.ch/SDT/cgi-bin/buildlogs/slc7_amd64_gcc11/CMSSW_12_1_X_2021-07-30-0900/DQM/SiStripCommissioningDbClients
Error message:
```
/data/cmsbld/jenkins/workspace/build-any-ib/w/tmp/BUILDROOT/3f7c5ca595fd8634b26b919adc27f210/opt/cmssw/slc7_amd64_gcc11/cms/cmssw/CMSSW_12_1_X_2021-07-30-0900/src/DQM/SiStripCommissioningDbClients/src/FastFedCablingHistosUsingDb.cc: In member function 'void FastFedCablingHistosUsingDb::connections(SiStripConfigDb::DeviceDescriptionsRange, SiStripConfigDb::DcuDetIdsRange)':
/data/cmsbld/jenkins/workspace/build-any-ib/w/tmp/BUILDROOT/3f7c5ca595fd8634b26b919adc27f210/opt/cmssw/slc7_amd64_gcc11/cms/cmssw/CMSSW_12_1_X_2021-07-30-0900/src/DQM/SiStripCommissioningDbClients/src/FastFedCablingHistosUsingDb.cc:476:49: error: 'this' pointer is null [-Werror=nonnull]
476 | uint16_t npairs = idet->second->getApvNumber() / 2;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~
In file included from /data/cmsbld/jenkins/workspace/build-any-ib/w/slc7_amd64_gcc11/external/tkonlinesw/4.2.0-1_gcc7-fc776fdba2d2dc7e5bcd24170ad0d08e/include/TkDcuConversionFactors.h:30,
from /data/cmsbld/jenkins/workspace/build-any-ib/w/slc7_amd64_gcc11/external/tkonlinesw/4.2.0-1_gcc7-fc776fdba2d2dc7e5bcd24170ad0d08e/include/deviceType.h:30,
from /data/cmsbld/jenkins/workspace/build-any-ib/w/slc7_amd64_gcc11/external/tkonlinesw/4.2.0-1_gcc7-fc776fdba2d2dc7e5bcd24170ad0d08e/include/FecFactory.h:33,
from /data/cmsbld/jenkins/workspace/build-any-ib/w/slc7_amd64_gcc11/external/tkonlinesw/4.2.0-1_gcc7-fc776fdba2d2dc7e5bcd24170ad0d08e/include/DeviceFactory.h:26,
from /data/cmsbld/jenkins/workspace/build-any-ib/w/tmp/BUILDROOT/3f7c5ca595fd8634b26b919adc27f210/opt/cmssw/slc7_amd64_gcc11/cms/cmssw/CMSSW_12_1_X_2021-07-30-0900/src/OnlineDB/SiStripConfigDb/interface/SiStripConfigDb.h:17,
from /data/cmsbld/jenkins/workspace/build-any-ib/w/tmp/BUILDROOT/3f7c5ca595fd8634b26b919adc27f210/opt/cmssw/slc7_amd64_gcc11/cms/cmssw/CMSSW_12_1_X_2021-07-30-0900/src/DQM/SiStripCommissioningDbClients/interface/CommissioningHistosUsingDb.h:8,
from /data/cmsbld/jenkins/workspace/build-any-ib/w/tmp/BUILDROOT/3f7c5ca595fd8634b26b919adc27f210/opt/cmssw/slc7_amd64_gcc11/cms/cmssw/CMSSW_12_1_X_2021-07-30-0900/src/DQM/SiStripCommissioningDbClients/interface/FastFedCablingHistosUsingDb.h:5,
from /data/cmsbld/jenkins/workspace/build-any-ib/w/tmp/BUILDROOT/3f7c5ca595fd8634b26b919adc27f210/opt/cmssw/slc7_amd64_gcc11/cms/cmssw/CMSSW_12_1_X_2021-07-30-0900/src/DQM/SiStripCommissioningDbClients/src/FastFedCablingHistosUsingDb.cc:2:
/data/cmsbld/jenkins/workspace/build-any-ib/w/slc7_amd64_gcc11/external/tkonlinesw/4.2.0-1_gcc7-fc776fdba2d2dc7e5bcd24170ad0d08e/include/TkDcuInfo.h:126:13: note: in a call to non-static member function 'tscType32 TkDcuInfo::getApvNumber()'
126 | tscType32 getApvNumber( ) ;
| ^~~~~~~~~~~~
```