[Mageia-sysadm] Needs locking iurt chroot tarballs

[Thierry Vignaud]

Hi

Yesterday evening, iurt chroot was rebuild due to new rpm.
However some packages failed to build:
http://pkgsubmit.mageia.org/uploads/failure/cauldron/core/release/20120228010948.fwang.valstar.11974/log/botcmd.1330391389.jonund.log

D: [iurt_root_command] Running iurt_root_command --untar
/home/iurt/chroot_cauldron.x86_64.tar.gz
/home/iurt/chroot_tmp/iurt/chroot_cauldron...
D: [iurt_root_command] Uncompress tarball
gzip: stdin: unexpected end of file
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now
I: [iurt_root_command] ERROR: Uncompress tarball

There're 2 bugs:
1) build continues despite the tar failure
2) we should:
- either lock the chroot tarball when rebuilding it and when unpackagint it
  in order to prevent that to happen again
- ensure chroot tarball is updated atomically (temp tarball + single mv)

WDYT?