My bad, looks like those references do have something to do with it.

I made some more changes to the cross-build script, and tried again,
and the result was that the sysroot shows up in the linker's -L args
when compiling with that GHC, then stops showing up after removing
those references from the package.conf.d files for ghc-internal and
running ghc-pkg recache, then shows up with a new library directory if I
manually add it to the conf file and recache again.

It's possible the changes to the ksh cross-build script were needed in
tandem with removing the references, but I doubt it. I think it's more
likely I made a mistake last time and removed the references from the
extracted tarball instead of the install prefix after $ gmake install.

However, I'm unable to embed the -Wl,--no-execute-only into the linker
arguments with stage1.*.ghc.c.opts (nor do I get a grep match for the
-fno-ret-protector flag in the compiler or linker arguments anyway, so
I must have misunderstood how it's producing working aarch64 binaries
after that change).

Cheers,
Habib