Re: kbd 2.9.0: build error (under fakeroot(1) environment)

Alexey Gladkov wrote in
 <[email protected]>:
 |On Tue, Sep 09, 2025 at 11:18:18PM +0200, Steffen Nurpmeso wrote:
 |> Alexey Gladkov wrote in
 |>  <[email protected]>:
 |>|On Tue, Sep 09, 2025 at 03:45:33PM +0200, Steffen Nurpmeso wrote:
 |>|> My distribution (CRUX) updated to 2.9.0, and the build failed via
 |>|> 
 |>|>   cp: failed to preserve ownership for /tmp/.pkgmk/pkg/usr/share/kbd/ke\
 |>|>   ym\
 |>|>   aps/i386/qwertz/sr-latin.map.gz: Operation not supported
 |>|> 
 |>|> Thing is that this seems to only work for real root user, but that
 |>|> is not who is doing it, really.
 |>|
 |>|cp -a is used in the makefile. The -a means no dereference and preserve
 |>|links and other attributes. This should not be a problem if you have
 |>|the same user.
 |> 
 |> GNU coreutils 9.7 cp(1) is of a different opinion:
 |> 
 |>   $ touch xa
 |>   $ ln -s xa xb
 |>   $ cp -a xb xc
 |>   cp: failed to preserve ownership for xc: Operation not supported
 |
 |No. This is security settings on your system.
 |
 |On my laptop:
 |
 |$ touch xa
 |$ ln -s xa xb
 |$ cp -a xb xc

 |$ ls -la
 |total 8
 |drwxr-xr-x  2 legion legion 4096 Sep 10 11:30 .
 |drwxr-xr-x 15 legion legion 4096 Sep 10 11:30 ..
 |-rw-r--r--  1 legion legion    0 Sep 10 11:30 xa
 |lrwxrwxrwx  1 legion legion    2 Sep 10 11:30 xb -> xa
 |lrwxrwxrwx  1 legion legion    2 Sep 10 11:30 xc -> xa

 |$ cp --version | head -1
 |cp (GNU coreutils) 9.7

This is really strange; i have no "security setting", actually,
only the fs.protected_* sysctls are set.
I get the failure in the "sticky" /tmp/ as well as as myself in my
home directory.  Looking at coreutils cp.c the error comes from

      if (x->preserve_ownership)
        {
          if (lchownat (dst_dirfd, relname, p->st.st_uid, p->st.st_gid)
              != 0)
...
                  error (0, errno, _("failed to preserve ownership for %s"),
                         quoteaf (dst_name));

Here there is no lchownat(3/2), and if i do (copied from manual
and made runnable)

             #include <sys/types.h>
             #include <unistd.h>
             #include <pwd.h>
             #include <grp.h>
  #include <errno.h>
  #include <string.h>
  #include <stdio.h>
  int main(void){
             struct passwd *pwd;
             struct group  *grp;
             int x;

             pwd = getpwnam("steffen");
             grp = getgrnam("steffen");
             x = lchown("xb", pwd->pw_uid, grp->gr_gid);
             fprintf(stderr, "x=%d errno=%s\n", x, strerror(errno));
             return 0;
  }

i get

  #?148|kent:x$ fakeroot tcc -run t.c
  x=0 errno=Success
  #?0|kent:x$ tcc -run t.c
  x=0 errno=Success

wherever i try, and so it seems to me the GNU coreutils
lib/fchownat.c fallback implementation of lchownat() is bogus
thus??

  ...
 |>|You can try to change "cp -a" by "cp -dPR". Maybe this will help with
 |>|fakeroot.
 |> 
 |> Yes, it does.
 |
 |Good. Thanks!
 |
 |https://web.git.kernel.org/pub/scm/linux/kernel/git/legion/kbd.git/commi\
 |t/?id=db82eb6f86e6c0b8ac4260e88b88d66e1cd7c077

Ah, and the kernel.org "you are not a robot check" is totally
bogus.  If i go directly to

  https://git.kernel.org/pub/scm/linux/kernel/git/legion/kbd.git/commit/?id=db82eb6f86e6c0b8ac4260e88b88d66e1cd7c077

i get over it, but if i follow your link i get in an endless loop
that tries and restarts and tries and restarts.  Some lwn.net
article link i followed (on git and rust, led to still running
FreeBSD bikeshed "Re: Git haas gone wild (Rust), freebsd-update"
thread on freebsd-hackers@) always ends up as "Noes!" or
something.  Just in case ..  (Luckily with lynx(1) direct access
is possible without that script mess.)

So anyway the commit message of yours is not right ;), and, do you
know people of coreutils, or is this worth a bug report?

  ...

Ciao -- and thanks for the fast fix!

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)