Crap, looks like I've found it. Nixos/nixpkgs trees I used recently were obtained from git mirror. I tried to update using a tree directly from svn (of corresponding revision) - and it worked! nix successfully installed vlc using substitution. vlc expressions are the same in both trees. If I understand correctly, that means that they have different derivations for some reason, svn is lucky and produces a correct one. But damn, now nixos-rebuild doesn't want to write a path to this derivation for me, and I can't compare it with the one of git-tree. oh, tired of mysteries..
Anyway, thanks.. 2012/6/3 Sergey Mironov <[email protected]>: > Thanks for quick answer > > > > 2012/6/3 Eelco Dolstra <[email protected]>: >> Hi, >> >> On 02/06/12 16:25, Sergey Mironov wrote: >> >>> We know that vlc package depends on a52dec. We have a substitution for vlc: >>> >>> $ sudo nix-env -qas 'vlc' --system --out-path >>> --S vlc-2.0.1 x86_64-linux >>> /nix/store/x332qx57qbak8rbmg4hhbjr5m7afn2df-vlc-2.0.1 >>> --S vlc-2.0.1 i686-linux >>> /nix/store/vwvz7hh1yc1bvjn6avylbzlgib8d2b60-vlc-2.0.1 >>> --S vlc-2.0.1 i686-linux >>> /nix/store/vwvz7hh1yc1bvjn6avylbzlgib8d2b60-vlc-2.0.1 >>> (hm.. why are there two of them. ok, let it be so) >> >> I only have one. Maybe you have multiple channels (e.g. nixos-unstable and >> nixpkgs-unstable)? If you want to find out where they're coming from, use >> the >> -P flag to see the corresponding attribute name. > > O, thanks, with -P flag it says > > $ sudo nix-env -qas 'vlc' --system --out-path -P > --S latest.0 vlc-2.0.1 x86_64-linux > /nix/store/x332qx57qbak8rbmg4hhbjr5m7afn2df-vlc-2.0.1 > --S latest.1 vlc-2.0.1 i686-linux > /nix/store/vwvz7hh1yc1bvjn6avylbzlgib8d2b60-vlc-2.0.1 > --S nixos.pkgs.vlc vlc-2.0.1 i686-linux > /nix/store/vwvz7hh1yc1bvjn6avylbzlgib8d2b60-vlc-2.0.1 > > where "latest" is the name of vlc's channel I've added, but then > removed (!). Currently, my user's ~/.nix-channel is empty and root's > ~/.nix-channel contains only reference to nixos-latest. Probably there > is another cache elsewhere, maybe nix-env has one? (oh, I've found the > place: ~/.nix-defexp/channels/latest -> vlc's manifest. May it be a > result of unlucky Ctrl+C ?) Anyway, probably It is not a major > problem. > >>> Threre is no substitute for a52dec! (And for some reason I can't find >>> a52dec job on a hydra website). How did hydra compile vlc without >>> building a52dec? If it actually did compile a52dec, then what is wrong >>> with it's substitution? >> >> This is because a52dec is only a build-time dependency and not a runtime >> dependency. (This might suggest that vlc doesn't actually do anything with >> a52dec, in which case it should be removed as a dependency...) So Hydra does >> build it, but it doesn't end up in the channel because the channel only >> contains >> runtime dependencies. >> >> (In the past the Nixpkgs channel also contained build-time dependencies.) >> > > The actual reason I started investigation is the behavior of > nixos-rebuild. It wants to build derivations for vlc and a52dec > locally. By the way, a52dec is plainly listed in vlc's buildInputs. > How can nix determine that it is a built-time dep without building vlc > and scanning it's binary? > > In general, Is it possible to ask nix, why does it want to build a52dec? > > [~/proj/nix] $ sudo nixos-rebuild -I . dry-run > building Nix... > building the system configuration... > these derivations will be built: > /nix/store/7g09vsdbp72zhbd0pkada0klynmax153-etc.drv > /nix/store/8ha1qnpy6havqb468xzzhy3nr6gr47xl-upstart-xserver.conf.drv > /nix/store/9zqw7kri0n7i138rzv25dc0zqa3fcqyy-nixos-0.1pre-svn.drv > /nix/store/h2y1c5gaa5x1h34qx3jyf42n8knkzjwb-system-crontab.drv > /nix/store/lvghnv1ifyx3jw10icvy2nvf4hmj5z2z-system-path.drv > /nix/store/n2fwa36yjl0acrvglhh79mb615g84h44-slim.cfg.drv > /nix/store/pnwplhaa56nqjshsy9karl692kdigdwz-vlc-2.0.1.drv > /nix/store/x90bxbllmwz41q7mvs5lbiy3apxab900-dbus-conf.drv > /nix/store/xjcp6j81yjclkrsndk0kn459mpm8sygq-xsession.drv > (a52dec is already locally compiled and doesn't mentioned here) > > PS > My custom dev tree is basically a current svn-head + some new > packages. All packages are installed via nixos-config, nix-env -q '*' > is empty for all users. _______________________________________________ nix-dev mailing list [email protected] http://lists.science.uu.nl/mailman/listinfo/nix-dev
