gnulib has added emulation of lchmod, fchmodat based on /proc, and glibc upstream will do so as well. We need to integrate the glibc changes into Fedora so that GNU applications can be built properly.
We're hitting an XFS bug in this area: https://www.sourceware.org/ml/libc-alpha/2020-02/msg00467.html
The kernel bug is worked around with this glibc commit: commit a492b1e5ef7ab50c6fdd4e4e9879ea5569ab0a6c Author: Florian Weimer <fweimer> Date: Tue Feb 18 17:52:27 2020 +0100 Linux: Work around kernel bugs in chmod on /proc/self/fd paths [BZ #14578] It appears that the ability to change symbolic link modes through such paths is unintended. On several file systems, the operation fails with EOPNOTSUPP, even though the symbolic link permissions are updated. The expected behavior is a failure to update the permissions, without file system changes. Reviewed-by: Matheus Castanho <msc.com>
I'd really like to wait with the backports until the kernel system call has landed. I've pinged the most recent submission.
This bug appears to have been reported against 'rawhide' during the Fedora 33 development cycle. Changing version to 33.
Rick Felker posted an implementation of the required system call: https://lore.kernel.org/linux-api/20200910142335.GG3265@brightrain.aerifal.cx/
Rich Felker's patch was rejected because it did not come with a test case. We probably need to contribute that test case so that the kernel change can move forward.
Fixed by: * Wed Feb 26 2020 Patsy Franklin <patsy> - 2.31.9000-1 - Auto-sync with upstream branch master, commit 758599bc9dcc5764e862bd9e1613c5d1e6efc5d3.