O2 compilation failure due to missing *boost_python*

Sorry for bothering you. I am sure that I am missing something.
Before yesterday, I tried to install O2 from scratch (aliBuild init O2@dev --defaults o2 ; aliBuild build O2 --defaults o2 --debug). Usually it worked. However, at this time, compilation failed due to missing boost_python libraries.

Last lines in the log said:
DEBUG:O2:0:
DEBUG:O2:0: ln -f -s ‘libboost_contract.so.1.70.0’ ‘/home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/libboost_contract.so’
DEBUG:O2:0:
DEBUG:O2:0: ln-UNIX /home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/libboost_contract.so.1
DEBUG:O2:0:
DEBUG:O2:0: ln -f -s ‘libboost_contract.so.1.70.0’ ‘/home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/libboost_contract.so.1’
DEBUG:O2:0:
DEBUG:O2:0: ln-UNIX /home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/libboost_contract.so.1.70
DEBUG:O2:0:
DEBUG:O2:0: ln -f -s ‘libboost_contract.so.1.70.0’ ‘/home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/libboost_contract.so.1.70’
DEBUG:O2:0:
DEBUG:O2:0: …updated 15633 targets…
DEBUG:O2:0: + rm -Rf /home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/cmake
DEBUG:O2:0: + [[ -n 1 ]]
DEBUG:O2:0: + ls -1 ‘/home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/boost_python
DEBUG:O2:0: ls: cannot access /home/gunji/aliceO2.new/2019Dec/sw/INSTALLROOT/a6030c502b01094636d558e3aaa17c463dad1993/slc7_x86-64/boost/v1.70.0-1/lib/boost_python: No such file or directory
DEBUG:O2:0:
ERROR:O2:0: Error while executing /home/gunji/aliceO2.new/2019Dec/sw/SPECS/slc7_x86-64/boost/v1.70.0-1/build.sh on `alitpcdaq02’.

I appreciate your help.
My os is CentOS Linux release 7.7.1908 (Core) and gcc version is 7.3.1.

Cheers, Taku