examples: add a broken example case

Recent changes in the 6.15-rc kernel series have broken
composefs-setup-root when running without using the newest features of
the mount API (ie: with the pre-6.15 feature left enabled, which is the
default).

Add a case to the examples for testing that.  Once it gets working again
it would be useful to make sure it continues to work.

Signed-off-by: Allison Karlitskaya <[email protected]>

Author: allisonkarlitskaya

examples/bls/build

@@ -24,6 +24,13 @@ case "${os}" in
         containerfile='Containerfile.ubuntu'
         cargo build --release --features=pre-6.15
         ;;
+    rawhide-compat)
+        # try a variant with rawhide using the old mount APIs
+        # this is currently failing due to a suspected kernel behaviour change
+        # https://lore.kernel.org/linux-fsdevel/CAOYeF9WQhFDe+BGW=Dp5fK8oRy5AgZ6zokVyTj1Wp4EUiYgt4w@mail.gmail.com
+        containerfile='Containerfile.rawhide'
+        cargo build --release --features=pre-6.15
+        ;;
     rawhide)
         containerfile='Containerfile.rawhide'
         cargo build --release --no-default-features --features=oci