MemorySanitizer: use-of-uninitialized-value

[metrapoliten]

I ran CI with MemorySanitizer and the LLVM22 toolchain and got an error inside the module (master version):

stderr: ==3893==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x56308eb69f5b in std::__1::basic_ostream<char, std::__1::char_traits<char>>& std::__1::__put_character_sequence[abi:nqe220103]<char, std::__1::char_traits<char>>(std::__1::basic_ostream<char, std::__1::char_traits<char>>&, char const*, unsigned long) /usr/lib/llvm-22/include/c++/v1/__ostream/put_character_sequence.h:35:9
    #1 0x56308eb67130 in std::__1::basic_ostream<char, std::__1::char_traits<char>>& std::__1::operator<<[abi:nqe220103]<std::__1::char_traits<char>>(std::__1::basic_ostream<char, std::__1::char_traits<char>>&, char const*) /usr/lib/llvm-22/include/c++/v1/__ostream/basic_ostream.h:438:10
    #2 0x56308eb67130 in boost::ext::ut::v2_3_1::runner@boost.ut<boost::ext::ut::v2_3_1::reporter_junit@boost.ut<boost::ext::ut::v2_3_1::printer@boost.ut>, 16>::runner() /home/runner/work/conv/conv/deps/ut/ut.hpp:2010:15
    #3 0x56308eab1a0a in __cxx_global_var_init /home/runner/work/conv/conv/deps/ut/ut.hpp:2216:36
    #4 0x7f791d42a303 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2a303) (BuildId: 8e9fd827446c24067541ac5390e6f527fb5947bb)
    #5 0x56308eab2dc4 in _start (/home/runner/work/conv/conv/build/linux/x86_64/MSan/test+0x3fdc4) (BuildId: efec1ef32f26815622fbda412a6359b5509afda0)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /home/runner/work/conv/conv/deps/ut/ut.hpp:2010:15 in boost::ext::ut::v2_3_1::runner@boost.ut<boost::ext::ut::v2_3_1::reporter_junit@boost.ut<boost::ext::ut::v2_3_1::printer@boost.ut>, 16>::runner()

The error occurs locally as well. As far as I understand, this is a problem with libc++, not with the module?