clang-10 fails to compile Argum: no viable overloaded '='

In file included from /wrkdirs/usr/ports/science/agrum/work/aGrUM-676cfe5833f09b013f2612ee299a9025793928d8-676cfe5833f09b013f2612ee299a9025793928d8/src/agrum/learning/structureUtils/graphChangesGeneratorOnSubDiGraph.cpp:30:
In file included from /wrkdirs/usr/ports/science/agrum/work/aGrUM-676cfe5833f09b013f2612ee299a9025793928d8-676cfe5833f09b013f2612ee299a9025793928d8/src/agrum/learning/structureUtils/graphChangesGeneratorOnSubDiGraph.h:238:
/wrkdirs/usr/ports/science/agrum/work/aGrUM-676cfe5833f09b013f2612ee299a9025793928d8-676cfe5833f09b013f2612ee299a9025793928d8/src/agrum/learning/structureUtils/graphChangesGeneratorOnSubDiGraph_tpl.h:215:19: error: no viable overloaded '='
      _tail_nodes = node;
      ~~~~~~~~~~~ ^ ~~~~

FreeBSD 12

Full log: http://beefy18.nyi.freebsd.org/data/head-amd64-default/p528551_s359028/logs/agrum-0.16.4_2.log (IPv6 URL)