warning: unstable feature specified for `-Ctarget-feature`: `backchain`

kernel test robot <[email protected]>
Newsgroups dev.linux.lists.llvm,dev.linux.lists.oe-kbuild-all,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53
commit: 3f70ebe638581e73c8df6b3fa7eed9b45d90b083 s390: Enable Rust support
date:   4 weeks ago
config: s390-randconfig-001-20260707 (https://download.01.org/0day-ci/archive/20260707/[email protected]/config)
compiler: clang version 21.1.8 (https://github.com/llvm/llvm-project 2078da43e25a4623cab2d0d60decddf709aaea28)
rustc: rustc 1.96.0 (ac68faa20 2026-05-25)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260707/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Fixes: 3f70ebe63858 ("s390: Enable Rust support")
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

>> warning: unstable feature specified for `-Ctarget-feature`: `backchain`
   |
   = note: this feature is not stably supported; its behavior can change in the future

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.