Failed sanity check at LFS 5.7.Glibc-2.29
Solution 1:
I'm on a path of compiling LFS in a different directory just like you. I followed the same steps as you have. And have gotten the exact same results.
But I think I have one hint, you haven't mentioned:
/path/to/my/folder/tools/bin/x86_64-lfs-linux-gnu-ld /path/to/my/folder/tools/lib/libc.so.6
Gives warning:
x86_64-lfs-linux-gnu-ld: warning: cannot find entry symbol _start; not setting start address
Hope this can help uncover the problem.