#112 p7zip 9.20 - "unsupported method" with RAR files

my space
Gabriel Cossette


I upgraded to p7zip 9.20 and now if I try to extract some RAR files, I get this error:

"Unsupported method"

I'm using Arch Linux package BTW: http://www.archlinux.org/packages/extra/i686/p7zip/

I'll keep using version 9.13 in the meantime...



  • Anonymous

    Tested with v9.20 under Mac OSX 10.6.6 ( built using macosx_32bits_asm ) : Rar extraction works fine.

  • Maybe it's only happening on Linux then?

  • my p7zip
    my p7zip

    Before providing p7zip, I tests on several Linux "rar extraction".

    What command did you use ?

    7z x my_archive.rar.

    7za does not understand rar archives.

    7z needs the rar codec to be able to unrar.

    Perhaps Arch Linux now follows the "debian/Ubuntu" rules.

    There is one package for the LGPL part of p7zip (7za, 7z)
    and one non-Free package for the unrar codec.

    Please search for all the p7zip packages provided by Arch Linux.

  • Martin Panter
    Martin Panter

    I can reproduce this problem with the p7zip-9.20-1-x86_64 on Arch Linux. The "7z" command says "unsupported method" for Rar files that are compressed. It looks like the Rar codec is not present in this package. If you install usr/lib/p7zip/Codecs/Rar29.so then it works.

    The reason behind this is Arch Linux calls "make install", which runs install.sh, which has been changed between 9.13 and 9.20 to no longer install the "Codecs" directory. Not sure on the reasoning for this; it might be more obvious if it was mentioned in the change log or there was a version control. Diff of 9.13 to 9.20:
    --- p7zip_9.13/install.sh 2008-03-02 13:35:05.000000000 +0000
    +++ p7zip_9.20/install.sh 2011-02-23 20:00:34.000000000 +0000
    @@ -83,20 +97,10 @@ then
    chmod 555 "${DEST_DIR}${DEST_SHARE}/7zCon.sfx"

    - if [ -x bin/7z ]
    + if [ -x bin/7z.so ]
    - echo "- installing ${DEST_DIR}${DEST_BIN}/7z"
    - cp bin/7z "${DEST_DIR}${DEST_SHARE}/7z"
    - chmod 777 "${DEST_DIR}${DEST_SHARE}/7z"
    - strip "${DEST_DIR}${DEST_SHARE}/7z"
    - chmod 555 "${DEST_DIR}${DEST_SHARE}/7z"
    - cp -r bin/Codecs "${DEST_DIR}${DEST_SHARE}/"
    - chmod 555 "${DEST_DIR}${DEST_SHARE}"/*/*
    cp bin/7z.so "${DEST_DIR}${DEST_SHARE}/7z.so"
    chmod 555 "${DEST_DIR}${DEST_SHARE}/7z.so"
    - echo "#! /bin/sh" > "${DEST_DIR}${DEST_BIN}/7z"
    - echo "\"${DEST_SHARE}/7z\" \"\$@\"" >> "${DEST_DIR}${DEST_BIN}/7z"
    - chmod 555 "${DEST_DIR}${DEST_BIN}/7z"


  • So I understand that the Rar codec can still be compiled/included in the package. So it's a problem with Arch package.

    I'll file a bug in Arch about that. I don't think it's a licensing issue as Arch has been very flexible on that side, being based in Canada instead of the US.

    Thanks a lot guys!

  • Martin Panter
    Martin Panter

    My guess is the "cp -r bin/Codecs" line was accidentally deleted, so it should be fixed in the "p7zip" project, not in Arch.

  • my p7zip
    my p7zip

    • assigned_to: nobody --> myspace
  • my p7zip
    my p7zip

    install.sh was changed but not enough tested ...

    So there is a but in install.sh which does not install Codecs/Rar29.so.

    Sorry for the bug ...

  • Thanks for the investigation all!

    Glad we found where the real bug lies ;)

    • status: open --> pending
  • my p7zip
    my p7zip

    • status: pending --> closed-fixed
  • my p7zip
    my p7zip

    install.sh fixed in p7zip 9.20.1