While cross-compiling the 'igt-gpu-tools-1.23' tag in the ChromeOS environment, which uses Clang, I observed the following error:
tests/gem_userptr_blits.c:1092:10: error: implicit declaration of function 'memfd_create' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
memfd = memfd_create("pages", 0);
This issue is resolved by the following commit (20 commits after tag):
bcb37a9 build: provide stub implementation for memfd_create
As you noted, Lucas landed a patch shortly after the 1.23 release that addressed this. Since that time an official 1.24 release has come out, so I don't believe there's anything further that needs to be done with this bug. Closing as resolved.