(In reply to Aaron Puchert from comment #3) > Could you try running with valgrind? After compilation of Falkon has failed: $ cd src/plugins/PyFalkon $ LC_ALL=C eval valgrind `grep -o '/usr/bin/shiboken2 .*' CMakeFiles/PyFalkon_autogen.dir/build.make` The relevant part of the output: Process terminating with default action of signal 11 (SIGSEGV): dumping core General Protection Fault at 0x123878FD: ??? (in /memfd:sljit (deleted)) by 0x12872367: ???