unsquashfs_xattr.c:28:24: error: attr/xattr.h: File or directory not found
The file is in sys/, not attr/, on my systems. sed -i 's@attr/xattr.h@sys/xattr.h@' *.c
and your systems are running which distro?
LFS. But I don't see how this is relevant.
"getxattr() and friends can be provided by glibc or by the standalone libattr library."
I don't have libattr installed, and it is not needed for xattrs. As said in the link above, the glibc header is in sys/, while libattr puts the (completely same usage-wise) header into attr/. I don't think you should depend on libattr when this functionality is in glibc.
It is a bit confusing having two files called xattr.h and one of them is in the wrong include path.
Am using Mainline .36 kernel on Mandriva.
Fxed in git.