Mine was compiled on March 3rd, d95039d, this commit is not available now. The issue you linked was reported on Feb 1st, so I think the issue is not in lldb-zig.
/usr/include/c++/9/
Your gcc is kinda old, I think the problem is in compilerās std. I used gcc 14 to compile the debugger. I will try to compile latest commit again, will report the results later, it will take a while 
EDIT: build is successful, so I would blame old gcc.