LTO build failure

[Alessandro-Barbieri]

gentoo CI tried to build with LTO and failed
see https://bugs.gentoo.org/860537
log https://860537.bugs.gentoo.org/attachment.cgi?id=793916

.libs/libSharedComponents_la-PRVStatesDataExtractor.o
/bin/sh ../../libtool  --tag=CXX   --mode=compile x86_64-pc-linux-gnu-g++ -DHAVE_CONFIG_H -I. -I../..  -DCLUSTERING_SUITE -I/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/include -I/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/src/BasicClasses -I/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/common_utilities -I/usr/include/libxml2 -I/usr/include -I/usr/include -I../../src/libClustering -I../../src/libParaverTraceParser -I/usr/include/ANN  -I../../pcfparser_svn3942   -O2 -pipe -march=x86-64 -frecord-gcc-switches -fno-diagnostics-color -fmessage-length=0 -flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -c -o libSharedComponents_la-PRVEventsDataExtractor.lo `test -f 'PRVEventsDataExtractor.cpp' || echo './'`PRVEventsDataExtractor.cpp
libtool: compile:  x86_64-pc-linux-gnu-g++ -DHAVE_CONFIG_H -I. -I../.. -DCLUSTERING_SUITE -I/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/include -I/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/src/BasicClasses -I/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/common_utilities -I/usr/include/libxml2 -I/usr/include -I/usr/include -I../../src/libClustering -I../../src/libParaverTraceParser -I/usr/include/ANN -I../../pcfparser_svn3942 -O2 -pipe -march=x86-64 -frecord-gcc-switches -fno-diagnostics-color -fmessage-length=0 -flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -c PRVEventsDataExtractor.cpp  -fPIC -DPIC -o .libs/libSharedComponents_la-PRVEventsDataExtractor.o
In file included from DataExtractor.hpp:46,
                 from DataExtractor.cpp:35:
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetClusteringPoints()':
./TraceData.hpp:179:38: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  179 |       return (vector<const Point*>&) ClusteringBursts;
      |                                      ^~~~~~~~~~~~~~~~
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetCompletePoints()':
./TraceData.hpp:182:84: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  182 | >& GetCompletePoints(void) { return (vector<const Point*>&) CompleteBursts; };
      |                                                             ^~~~~~~~~~~~~~

In file included from DataExtractor.hpp:46,
                 from DataExtractorFactory.hpp:45,
                 from DataExtractorFactory.cpp:35:
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetClusteringPoints()':
./TraceData.hpp:179:38: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  179 |       return (vector<const Point*>&) ClusteringBursts;
      |                                      ^~~~~~~~~~~~~~~~
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetCompletePoints()':
./TraceData.hpp:182:84: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  182 | >& GetCompletePoints(void) { return (vector<const Point*>&) CompleteBursts; };
      |                                                             ^~~~~~~~~~~~~~

cc1plus: some warnings being treated as errors
make[4]: *** [Makefile:748: libSharedComponents_la-DataExtractor.lo] Error 1
make[4]: *** Waiting for unfinished jobs....
cc1plus: some warnings being treated as errors
make[4]: *** [Makefile:755: libSharedComponents_la-DataExtractorFactory.lo] Error 1
In file included from DataExtractor.hpp:46,
                 from PRVStatesDataExtractor.hpp:40,
                 from PRVStatesDataExtractor.cpp:38:
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetClusteringPoints()':
./TraceData.hpp:179:38: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  179 |       return (vector<const Point*>&) ClusteringBursts;
      |                                      ^~~~~~~~~~~~~~~~
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetCompletePoints()':
./TraceData.hpp:182:84: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  182 | >& GetCompletePoints(void) { return (vector<const Point*>&) CompleteBursts; };
      |                                                             ^~~~~~~~~~~~~~

In file included from DataExtractor.hpp:46,
                 from PRVEventsDataExtractor.hpp:40,
                 from PRVEventsDataExtractor.cpp:38:
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetClusteringPoints()':
./TraceData.hpp:179:38: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  179 |       return (vector<const Point*>&) ClusteringBursts;
      |                                      ^~~~~~~~~~~~~~~~
./TraceData.hpp: In member function 'std::vector<const Point*>& TraceData::GetCompletePoints()':
./TraceData.hpp:182:84: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-aliasing]]
  182 | >& GetCompletePoints(void) { return (vector<const Point*>&) CompleteBursts; };
      |                                                             ^~~~~~~~~~~~~~

cc1plus: some warnings being treated as errors
make[4]: *** [Makefile:762: libSharedComponents_la-PRVStatesDataExtractor.lo] Error 1
cc1plus: some warnings being treated as errors
make[4]: *** [Makefile:769: libSharedComponents_la-PRVEventsDataExtractor.lo] Error 1
make[4]: Leaving directory '/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/src/libSharedComponents'
make[3]: *** [Makefile:938: all-recursive] Error 1
make[3]: Leaving directory '/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/src/libSharedComponents'
make[2]: *** [Makefile:449: all-recursive] Error 1
make[2]: Leaving directory '/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9/src'
make[1]: *** [Makefile:678: all-recursive] Error 1
make[1]: Leaving directory '/var/tmp/portage/sys-cluster/clusteringsuite-2.6.9-r3/work/clustering-suite-2.6.9'
make: *** [Makefile:589: all] Error 2