TarScm (cpio): fix symlink time stamps

[mwilck]

Symlinks in .obscpio archives don't have the source time stamp. This
may cause non-reproducible .obscpio files.
Fix this by using the "follow_symlinks" option of os.utime().

[mwilck]

FTR, the CI failure doesn't seem to be caused by my patch.

[mwilck]

ping...

[mwilck]

ping…

[M0ses]

Pong - Could you provide a test case?

[mwilck]

Sorry, this is not how it works. I'm providing a bug fix, and a rather obvious one for that matter. Rather than saying "thank you", you're asking me to invest more work into your project. I have no time for that, so either take it or leave it.

If you need a sample .obscpio file, see https://build.opensuse.org/package/show/Base:System/multipath-tools, which contains

lrwxrwxrwx   1 root     root           17 Jan  7 21:55 multipath-tools-0.8.8+13+suse.79c3556f/COPYING -> LICENSES/LGPL-2.0

This symlink causes osc service manualrun to create a cpio archive with a different checksum every time it's being run, because the time stamp differs. My patch avoids that in a trivial way by using the time stamp of the symlink's target rather than the time stamp of the symlink itself.