Hi, Guillem Jover wrote: >> diff --git a/lib/dpkg/compression-backend.c b/lib/dpkg/compression-backend.c >> index 8f0c055..4b4c9c3 100644 >> --- a/lib/dpkg/compression-backend.c >> +++ b/lib/dpkg/compression-backend.c >> @@ -25,7 +25,7 @@ >> >> static const char default_gz_compression = '9'; >> static const char default_bz2_compression = '9'; >> -static const char default_lzma_compression = '9'; >> +static const char default_lzma_compression = '\0'; >> >> static void fd_fd_filter(int fd_in, int fd_out, const char *desc, >> const char *file, const char *cmd, const char *argfmt, ...) > > I've not yet changed the default for the lzma compressor, but I'd like > to set it explicitly instead of relying on the library/command, I > guess 6 or 7 should be fine? (the lzma tool default to 7, xz to 6).
Yes. 6 should be fine. With lzma provided by xz [1], that uses about 8 MiB of resident memory on the decompressing end; with lzma provided by lzma, that uses about 4 MiB to decompress. Unfortunately, the pre-set compression levels have different meanings for the two versions (the gaps between 7 and 8 and 9 were too high, so upstream fixed it). If you want to distinguish the two versions, try “lzma --robot --version”: lzma provided by xz will say XZ_VERSION=(some integer) LIBLZMA_VERSION=(some other integer) whereas lzma from the current lzma package will give a one-line complaint and exit with status 1. The patch '[PATCH v2 2/4] dpkg-deb: set a memory usage limit for lzma -d' instead uses the heuristic that “lzma --version” provided by xz starts with "xz", but that is not guaranteed to hold forever. Regards, Jonathan [1] Since lzma is pseudo-essential, there is no way I know of without using diversions for two implementations to coexist, so for now we just don’t ship the lzma symlink from XZ Utils. But: - As soon as lzma is not essential any more, I will be packaging xz-lzma for experimental, and for unstable soon after if that goes well; - The xz-utils README.Debian encourages users to create that symlink themselves if they want it on their own $PATH. Thus I would prefer if dpkg still works without problems after a 'ln -s /usr/bin/xz /usr/local/bin/lzma' (or ~/bin/lzma). -- To UNSUBSCRIBE, email to debian-dpkg-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org