[[!summary chatGPT: How to fix the error message and update Nix archives in NixOS]]
[[!meta date="2012-06-06 19:50"]]
[[!tag nixos packagemanager]]
[[!img media/nixos-lores.png alt="" style="float: right"]]


# what is this?
lately nix-channel stopped working with this error message:

    # nix-channel --update
    fetching list of Nix archives at `http://nixos.org/releases/nixos/channels/nixos-unstable/MANIFEST.bz2'...
     % Total % Received % Xferd Average Speed Time Time Time Current
     Dload Upload Total Spent Left Speed
    100 421 100 421 0 0 5212 0 --:--:-- --:--:-- --:--:-- 10023
     0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
    caching /nix/store/2n6ifd0gyw3cg4v780yxdl307sfi4mmv-MANIFEST.bz2...
    bzip2: (stdin) is not a bzip2 file.
    you have an old-style or corrupt manifest `/nix/var/nix/manifests/nixos-unstable nixos-d8b23fa7b687df69ca99c50a659cb9b7.nixmanifest'; please delete it at /nix/store/gq4mqkg155jbpdzs44s6nc6ys1q3aqmh-nix-1.0pre2614_005d1e4/lib/perl5/site_perl/5.14.2/x86_64-linux-thread-multi/Nix/Manifest.pm line 346.
    cannot pull cache manifest from `http://nixos.org/releases/nixos/channels/nixos-unstable' at /var/run/current-system/sw/bin/nix-channel line 88.
    

# the fix


    # ls -la /nix/var/nix/manifests/
    
    total 28
    drwxr-xr-x 2 root root 4096 Jun 6 20:19 ./
    drwxr-xr-x 11 root root 4096 Jun 4 12:36 ../
    -rw-r--r-- 1 root root 0 Jun 6 19:44 cache.lock
    -rw-r--r-- 1 root root 10240 Jun 6 19:44 cache.sqlite
    -rw-r--r-- 1 root root 0 Jun 6 20:19 cache.sqlite-journal
    lrwxrwxrwx 1 root root 56 Jun 6 20:19 nixos-unstable-1b76fe40b585f44b15266540562d24b5.nixmanifest -> /nix/store/xrl4xmx6jz3zvcqwfy3k2qfycdh2454n-MANIFEST.bz2
    -rw-r--r-- 1 root root 64 Jun 6 20:19 nixos-unstable-1b76fe40b585f44b15266540562d24b5.url
    lrwxrwxrwx 1 root root 56 Jun 6 19:44 nixos-unstable\ nixos-d8b23fa7b687df69ca99c50a659cb9b7.nixmanifest -> /nix/store/2n6ifd0gyw3cg4v780yxdl307sfi4mmv-MANIFEST.bz2
    -rw-r--r-- 1 root root 70 Jun 6 19:44 nixos-unstable\ nixos-d8b23fa7b687df69ca99c50a659cb9b7.url


## first, remove all the manifests


    # rm /nix/var/nix/manifests/*


## then we can remove the store entry:


    # nix-store --delete /nix/store/xrl4xmx6jz3zvcqwfy3k2qfycdh2454n-MANIFEST.bz2 1 888 3 pts/17 /nix/var/nix/manifests root@eliteBook-8530w 12-06-06 21:35:59
    finding garbage collector roots...
    removing stale link from `/nix/var/nix/gcroots/auto/v6aa8ai44dd10ypv8vg6shf8b5mzkhfn' to `/nix/var/nix/gcroots/per-user/root/channels.tmp'
    deleting `/nix/store/xrl4xmx6jz3zvcqwfy3k2qfycdh2454n-MANIFEST.bz2'
    1 store paths deleted, 6557759 bytes (6.25 MiB, 12840 blocks) freed


## afterwards nix-channel --update works


    # nix-channel --update
    fetching list of Nix archives at `http://nixos.org/releases/nixos/channels/nixos-unstable/MANIFEST.bz2'...
     % Total % Received % Xferd Average Speed Time Time Time Current
     Dload Upload Total Spent Left Speed
    100 421 100 421 0 0 5191 0 --:--:-- --:--:-- --:--:-- 10023
     0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
    cached contents of ‘http://nixos.org/releases/nixos/channels/nixos-unstable/MANIFEST.bz2’ disappeared, redownloading...
     % Total % Received % Xferd Average Speed Time Time Time Current
     Dload Upload Total Spent Left Speed
    100 421 100 421 0 0 5221 0 --:--:-- --:--:-- --:--:-- 10268
    100 6404k 100 6404k 0 0 1499k 0 0:00:04 0:00:04 --:--:-- 1705k
    caching /nix/store/xrl4xmx6jz3zvcqwfy3k2qfycdh2454n-MANIFEST.bz2...
    downloading Nix expressions from `http://nixos.org/releases/nixos/channels/nixos-unstable/nixexprs.tar.bz2'...
     % Total % Received % Xferd Average Speed Time Time Time Current
     Dload Upload Total Spent Left Speed
    100 425 100 425 0 0 5417 0 --:--:-- --:--:-- --:--:-- 10365
    100 3701k 100 3701k 0 0 1404k 0 0:00:02 0:00:02 --:--:-- 1627k
    unpacking channel Nix expressions...
    these derivations will be built:
     /nix/store/4yd4l79h2nifm56rjpxq7hx10q57yz48-channels.drv
    building path(s) `/nix/store/r3i2m2by6hcsa3ic99nyhjdb7p551izl-channels'
    unpacking channel nixos-unstable


# summary


i don't know why it stopped working. maybe i did checkout the wrong channel by mistake? but maybe someone else might find himself in the same situation and this posting might help to get things going quickly.

thanks to niksnut@freenode#nixos