MD5 checksum failure returns incomprehensible message

[bcbc]

User ran Wubi.exe from CD. md5checksum failed. Message returned was: AttributeError: 'WindowsBackend' object has no attribute 'iso_path'.

I've seen other failures where this message is issued with no other indication of what the real error is (bug 876154).

Here is the logfile as reported from here: http://ubuntuforums.org/showpost.php?p=11353296&postcount=783

10-16 15:26 INFO root: === wubi 11.10 rev241 ===
10-16 15:26 DEBUG root: Logfile is c:\users\hulk\appdata\local\temp\wubi-11.10-rev241.log
10-16 15:26 DEBUG root: sys.argv = ['main.pyo', '--exefile="E:\\wubi.exe"', '--cdmenu']
10-16 15:26 DEBUG CommonBackend: data_dir=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\data
10-16 15:26 DEBUG WindowsBackend: 7z=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\bin\7z.exe
10-16 15:26 DEBUG WindowsBackend: startup_folder=C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup
10-16 15:26 DEBUG CommonBackend: Fetching basic info...
10-16 15:26 DEBUG CommonBackend: original_exe=E:\wubi.exe
10-16 15:26 DEBUG CommonBackend: platform=win32
10-16 15:26 DEBUG CommonBackend: osname=nt
10-16 15:26 DEBUG CommonBackend: language=en_US
10-16 15:26 DEBUG CommonBackend: encoding=cp1252
10-16 15:26 DEBUG WindowsBackend: arch=amd64
10-16 15:26 DEBUG CommonBackend: Parsing isolist=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\data\isolist.ini
10-16 15:26 DEBUG CommonBackend: Adding distro Xubuntu-i386
10-16 15:26 DEBUG CommonBackend: Adding distro Xubuntu-amd64
10-16 15:26 DEBUG CommonBackend: Adding distro Kubuntu-amd64
10-16 15:26 DEBUG CommonBackend: Adding distro Mythbuntu-i386
10-16 15:26 DEBUG CommonBackend: Adding distro Ubuntu-amd64
10-16 15:26 DEBUG CommonBackend: Adding distro Ubuntu-i386
10-16 15:26 DEBUG CommonBackend: Adding distro Mythbuntu-amd64
10-16 15:26 DEBUG CommonBackend: Adding distro Kubuntu-i386
10-16 15:26 DEBUG WindowsBackend: Fetching host info...
10-16 15:26 DEBUG WindowsBackend: registry_key=Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi
10-16 15:26 DEBUG WindowsBackend: windows version=vista
10-16 15:26 DEBUG WindowsBackend: windows_version2=Windows 7 Professional
10-16 15:26 DEBUG WindowsBackend: windows_sp=None
10-16 15:26 DEBUG WindowsBackend: windows_build=7601
10-16 15:26 DEBUG WindowsBackend: gmt=-5
10-16 15:26 DEBUG WindowsBackend: country=US
10-16 15:26 DEBUG WindowsBackend: timezone=America/New_York
10-16 15:26 DEBUG WindowsBackend: windows_username=hulk
10-16 15:26 DEBUG WindowsBackend: user_full_name=hulk
10-16 15:26 DEBUG WindowsBackend: user_directory=C:\Users\hulk
10-16 15:26 DEBUG WindowsBackend: windows_language_code=1033
10-16 15:26 DEBUG WindowsBackend: windows_language=English
10-16 15:26 DEBUG WindowsBackend: processor_name=AMD Phenom(tm) II X4 B55 Processor
10-16 15:26 DEBUG WindowsBackend: bootloader=vista
10-16 15:26 DEBUG WindowsBackend: system_drive=Drive(C: hd 423824.914063 mb free ntfs)
10-16 15:26 DEBUG WindowsBackend: drive=Drive(C: hd 423824.914063 mb free ntfs)
10-16 15:26 DEBUG WindowsBackend: drive=Drive(D: hd 324198.253906 mb free ntfs)
10-16 15:26 DEBUG WindowsBackend: drive=Drive(E: cd 0.0 mb free cdfs)
10-16 15:26 DEBUG WindowsBackend: drive=Drive(F: removable 3749.375 mb free fat32)
10-16 15:26 DEBUG WindowsBackend: uninstaller_path=None
10-16 15:26 DEBUG WindowsBackend: previous_target_dir=None
10-16 15:26 DEBUG WindowsBackend: previous_distro_name=None
10-16 15:26 DEBUG WindowsBackend: keyboard_id=67699721
10-16 15:26 DEBUG WindowsBackend: keyboard_layout=us
10-16 15:26 DEBUG WindowsBackend: keyboard_variant=
10-16 15:26 DEBUG CommonBackend: python locale=('en_US', 'cp1252')
10-16 15:26 DEBUG CommonBackend: locale=en_US.UTF-8
10-16 15:26 DEBUG WindowsBackend: total_memory_mb=4095.99999905
10-16 15:26 DEBUG CommonBackend: Searching ISOs on USB devices
10-16 15:26 DEBUG CommonBackend: Searching for local CDs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Ubuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Ubuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Kubuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Kubuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Xubuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Xubuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Mythbuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp is a valid Mythbuntu CD
10-16 15:26 DEBUG Distro: does not contain C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Ubuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Ubuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Kubuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Kubuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Xubuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Xubuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Mythbuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether D:\ is a valid Mythbuntu CD
10-16 15:26 DEBUG Distro: does not contain D:\casper\filesystem.squashfs
10-16 15:26 DEBUG Distro: checking whether E:\ is a valid Ubuntu CD
10-16 15:26 DEBUG Distro: parsing info from str=Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
10-16 15:26 DEBUG Distro: parsed info={'name': 'Ubuntu', 'subversion': 'Release', 'version': '11.10', 'build': '20111012', 'codename': 'Oneiric Ocelot', 'arch': 'amd64'}
10-16 15:26 INFO Distro: Found a valid CD for Ubuntu: E:\
10-16 15:26 INFO root: Running the CD menu...
10-16 15:26 DEBUG WindowsFrontend: __init__...
10-16 15:26 DEBUG WindowsFrontend: on_init...
10-16 15:26 INFO WinuiPage: appname=wubi, localedir=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\translations, languages=['en_US', 'en']
10-16 15:26 INFO WinuiPage: appname=wubi, localedir=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\translations, languages=['en_US', 'en']
10-16 15:26 INFO root: CD menu finished
10-16 15:26 INFO root: Running the installer...
10-16 15:26 INFO WinuiPage: appname=wubi, localedir=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\translations, languages=['en_US', 'en']
10-16 15:26 INFO WinuiPage: appname=wubi, localedir=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\translations, languages=['en_US', 'en']
10-16 15:26 DEBUG WinuiInstallationPage: target_drive=D:, installation_size=30000MB, distro_name=Ubuntu, language=en_US, locale=en_US.UTF-8, username=hulk
10-16 15:26 INFO root: Received settings
10-16 15:26 INFO WinuiPage: appname=wubi, localedir=C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\translations, languages=['en_US', 'en']
10-16 15:26 DEBUG TaskList: # Running tasklist...
10-16 15:26 DEBUG TaskList: ## Running select_target_dir...
10-16 15:26 INFO WindowsBackend: Installing into D:\ubuntu
10-16 15:26 DEBUG TaskList: ## Finished select_target_dir
10-16 15:26 DEBUG TaskList: ## Running create_dir_structure...
10-16 15:26 DEBUG CommonBackend: Creating dir D:\ubuntu
10-16 15:26 DEBUG CommonBackend: Creating dir D:\ubuntu\disks
10-16 15:26 DEBUG CommonBackend: Creating dir D:\ubuntu\install
10-16 15:26 DEBUG CommonBackend: Creating dir D:\ubuntu\install\boot
10-16 15:26 DEBUG CommonBackend: Creating dir D:\ubuntu\disks\boot
10-16 15:26 DEBUG CommonBackend: Creating dir D:\ubuntu\disks\boot\grub
10-16 15:26 DEBUG CommonBackend: Creating dir D:\ubuntu\install\boot\grub
10-16 15:26 DEBUG TaskList: ## Finished create_dir_structure
10-16 15:26 DEBUG TaskList: ## Running uncompress_target_dir...
10-16 15:26 DEBUG TaskList: ## Finished uncompress_target_dir
10-16 15:26 DEBUG TaskList: ## Running create_uninstaller...
10-16 15:26 DEBUG WindowsBackend: Copying uninstaller E:\wubi.exe -> D:\ubuntu\uninstall-wubi.exe
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi UninstallString D:\ubuntu\uninstall-wubi.exe
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi InstallationDir D:\ubuntu
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayName Ubuntu
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayIcon D:\ubuntu\Ubuntu.ico
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayVersion 11.10-rev241
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi Publisher Ubuntu
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi URLInfoAbout http://www.ubuntu.com
10-16 15:26 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi HelpLink http://www.ubuntu.com/support
10-16 15:26 DEBUG TaskList: ## Finished create_uninstaller
10-16 15:26 DEBUG TaskList: ## Running copy_installation_files...
10-16 15:26 DEBUG WindowsBackend: Copying C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\data\custom-installation -> D:\ubuntu\install\custom-installation
10-16 15:26 DEBUG WindowsBackend: Copying C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\winboot -> D:\ubuntu\winboot
10-16 15:26 DEBUG WindowsBackend: Copying C:\Users\hulk\AppData\Local\Temp\pylE49E.tmp\data\images\Ubuntu.ico -> D:\ubuntu\Ubuntu.ico
10-16 15:26 DEBUG TaskList: ## Finished copy_installation_files
10-16 15:26 DEBUG TaskList: ## Running get_iso...
10-16 15:26 DEBUG TaskList: New task copy_file
10-16 15:26 DEBUG TaskList: ### Running copy_file...
10-16 15:31 DEBUG TaskList: ### Finished copy_file
10-16 15:31 DEBUG TaskList: New task check_iso
10-16 15:31 DEBUG TaskList: ### Running check_iso...
10-16 15:31 DEBUG CommonBackend: Checking D:\ubuntu\install\installation.iso
10-16 15:31 DEBUG Distro: checking Ubuntu ISO D:\ubuntu\install\installation.iso
10-16 15:31 DEBUG WindowsBackend: extracting .disk\info from D:\ubuntu\install\installation.iso
10-16 15:31 DEBUG Distro: parsing info from str=Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
10-16 15:31 DEBUG Distro: parsed info={'name': 'Ubuntu', 'subversion': 'Release', 'version': '11.10', 'build': '20111012', 'codename': 'Oneiric Ocelot', 'arch': 'amd64'}
10-16 15:31 INFO Distro: Found a valid iso for Ubuntu: D:\ubuntu\install\installation.iso
10-16 15:31 DEBUG TaskList: New task get_metalink
10-16 15:31 DEBUG TaskList: #### Running get_metalink...
10-16 15:31 DEBUG downloader: downloading http://releases.ubuntu.com/11.10/ubuntu-11.10-desktop-amd64.metalink > D:\ubuntu\install
10-16 15:31 DEBUG downloader: Download start filename=D:\ubuntu\install\ubuntu-11.10-desktop-amd64.metalink, url=http://releases.ubuntu.com/11.10/ubuntu-11.10-desktop-amd64.metalink, basename=ubuntu-11.10-desktop-amd64.metalink, length=4899, text=None
10-16 15:31 DEBUG downloader: download finished (read 4899 bytes)
10-16 15:31 DEBUG downloader: downloading http://releases.ubuntu.com/11.10/MD5SUMS-metalink > D:\ubuntu\install
10-16 15:31 DEBUG downloader: Download start filename=D:\ubuntu\install\MD5SUMS-metalink, url=http://releases.ubuntu.com/11.10/MD5SUMS-metalink, basename=MD5SUMS-metalink, length=419, text=None
10-16 15:31 DEBUG downloader: download finished (read 419 bytes)
10-16 15:31 DEBUG downloader: downloading http://releases.ubuntu.com/11.10/MD5SUMS-metalink.gpg > D:\ubuntu\install
10-16 15:31 DEBUG downloader: Download start filename=D:\ubuntu\install\MD5SUMS-metalink.gpg, url=http://releases.ubuntu.com/11.10/MD5SUMS-metalink.gpg, basename=MD5SUMS-metalink.gpg, length=198, text=None
10-16 15:31 DEBUG downloader: download finished (read 198 bytes)
10-16 15:31 INFO saplog: Verified a signature from ID:'46181433FBB75451'.
10-16 15:31 INFO saplog: Checking block bindings..
10-16 15:31 INFO saplog: Key verified successfully.
10-16 15:31 DEBUG CommonBackend: metalink md5sums:
a65c220b437d6907ba9463b7f479fea5 ubuntu-11.10-alternate-amd64.metalink
bdbf5bf7dfa85cad2cd711f081b071ec ubuntu-11.10-alternate-i386.metalink
4a4ddfa7d6eea4d9cf7a9f8d854e0418 ubuntu-11.10-desktop-amd64.metalink
a84050d7b00ff42b83a69ad7309b6f36 ubuntu-11.10-desktop-i386.metalink
c2f7e1f7352a8d3cd1c2dede0c709a1a ubuntu-11.10-server-amd64.metalink
2b296035b3ba3f8536dc0efa49a52fc2 ubuntu-11.10-server-i386.metalink

10-16 15:31 DEBUG TaskList: #### Finished get_metalink
10-16 15:31 DEBUG TaskList: New task get_file_md5
10-16 15:31 DEBUG TaskList: #### Running get_file_md5...
10-16 15:32 DEBUG TaskList: #### Finished get_file_md5
10-16 15:32 ERROR CommonBackend: Invalid md5 for ISO D:\ubuntu\install\installation.iso (62fb5d750c30a27a26d01c5f3d8df459 != 6c222550f8330cb11cdc07c8f9a215c1)
None
10-16 15:32 DEBUG TaskList: ### Finished check_iso
10-16 15:32 ERROR TaskList: 'WindowsBackend' object has no attribute 'iso_path'
Traceback (most recent call last):
  File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__
  File "\lib\wubi\backends\common\backend.py", line 579, in get_iso
  File "\lib\wubi\backends\common\backend.py", line 565, in use_iso
AttributeError: 'WindowsBackend' object has no attribute 'iso_path'
10-16 15:32 DEBUG TaskList: # Cancelling tasklist
10-16 15:32 DEBUG TaskList: # Finished tasklist
10-16 15:32 ERROR root: 'WindowsBackend' object has no attribute 'iso_path'
Traceback (most recent call last):
  File "\lib\wubi\application.py", line 58, in run
  File "\lib\wubi\application.py", line 130, in select_task
  File "\lib\wubi\application.py", line 205, in run_cd_menu
  File "\lib\wubi\application.py", line 120, in select_task
  File "\lib\wubi\application.py", line 158, in run_installer
  File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__
  File "\lib\wubi\backends\common\backend.py", line 579, in get_iso
  File "\lib\wubi\backends\common\backend.py", line 565, in use_iso
AttributeError: 'WindowsBackend' object has no attribute 'iso_path'