Add more information to loopback mount failures.

Buildbots are periodically failing to build images; the evidence
points to failures in mount_gpt_image.sh, but it's inconclusive.
Add detailed error messages to mount failures so as to be able
to debug more the next time it happens.

BUG=chromium-os:24975
TEST=build_image, to see that successful cases still work
TEST=repeatedly mount new images with mount_gpt_image until it fails

Change-Id: I05a09c8eec46d9296a24ff36904a4aea20d2aae5
Reviewed-on: https://gerrit.chromium.org/gerrit/14433
Reviewed-by: David James <davidjames@chromium.org>
Tested-by: Richard Barnette <jrbarnette@chromium.org>
1 file changed
tree: e07b6d0436bbfcf58b7d4fd49edfa2c0cb9e992c
  1. bin/
  2. build_library/
  3. chroot_version_hooks.d/
  4. lib/
  5. mod_for_factory_scripts/
  6. mod_for_test_scripts/
  7. sdk_lib/
  8. .gitignore
  9. archive_hwqual
  10. bash_completion
  11. build_image
  12. build_kernel_image.sh
  13. call_autoserv.py
  14. check_control_files.sh
  15. clean_loopback_devices
  16. common.sh
  17. cros_deps_diff
  18. cros_generate_breakpad_symbols
  19. cros_generate_deps_graphs
  20. cros_generate_stacks_bvt
  21. cros_show_stacks
  22. dot_helper.py
  23. enable_localaccount.sh
  24. enter_chroot.sh
  25. exclude-list
  26. fixup_image_for_qemu.py
  27. get_latest_image.sh
  28. get_package_list
  29. image_to_usb.sh
  30. image_to_vm.sh
  31. make_netboot.sh
  32. mod_image_for_recovery.sh
  33. mod_image_for_test.sh
  34. mod_test_image_for_pyauto.sh
  35. mount_gpt_image.sh
  36. remote_access.sh
  37. run_chroot_version_hooks
  38. serve_factory_packages.py
  39. set_shared_user_password.sh
  40. sha256_partitions.sh
  41. ssh_test.sh
  42. start_devserver
  43. update_bootloaders.sh
  44. update_chroot
  45. update_kernel.sh
  46. upload_symbols
  47. verify_rootfs_chksum.sh