Version 0.8 NOTE: the hashing scheme in Nix 0.8 changed (as detailed below). As a result, `nix-pull' manifests and channels built for Nix 0.7 and below will now work anymore. However, the Nix expression language has not changed, so you can still build from source. Also, existing user environments continue to work. Nix 0.8 will automatically upgrade the database schema of previous installations when it is first run. If you get the error message you have an old-style manifest `/nix/var/nix/manifests/[...]'; please delete it you should delete previously downloaded manifests: $ rm /nix/var/nix/manifests/* If `nix-channel' gives the error message manifest `http://catamaran.labs.cs.uu.nl/dist/nix/channels/[channel]/MANIFEST' is too old (i.e., for Nix <= 0.7) then you should unsubscribe from the offending channel (`nix-channel --remove URL'; leave out `/MANIFEST'), and subscribe to the same URL, with `channels' replaced by `channels-v3' (e.g., http://catamaran.labs.cs.uu.nl/dist/nix/channels-v3/nixpkgs-unstable). Nix 0.8 has the following improvements: * The cryptographic hashes used in store paths are now 160 bits long, but encoded in base-32 so that they are still only 32 characters long (e.g., /nix/store/csw87wag8bqlqk7ipllbwypb14xainap-atk-1.9.0). (This is actually a 160 bit truncation of a SHA-256 hash.) * Big cleanups and simplifications of the basic store semantics. The notion of "closure store expressions" is gone (and so is the notion of "successors"); the file system references of a store path are now just stored in the database. For instance, given any store path, you can query its closure: $ nix-store -qR $(which firefox) ... lots of paths ... Also, Nix now remembers for each store path the derivation that built it (the "deriver"): $ nix-store -qR $(which firefox) /nix/store/4b0jx7vq80l9aqcnkszxhymsf1ffa5jd-firefox-1.0.1.drv So to see the build-time dependencies, you can do $ nix-store -qR $(nix-store -qd $(which firefox)) or, in a nicer format: $ nix-store -q --tree $(nix-store -qd $(which firefox)) File system references are also stored in reverse. For instance, you can query all paths that directly or indirectly use a certain Glibc: $ nix-store -q --referers-closure \ /nix/store/8lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4 * The concept of fixed-output derivations has been formalised. Previously, functions such as `fetchurl' in Nixpkgs used a hack (namely, explicitly specifying a store path hash) to prevent changes to, say, the URL of the file from propagating upwards through the dependency graph, causing rebuilds of everything. This can now be done cleanly by specifying the `outputHash' and `outputHashAlgo' attributes. Nix itself checks that the content of the output has the specified hash. (This is important for maintaining certain invariants necessary for future work on secure shared stores.) * One-click installation :-) It is now possible to install any top-level component in Nixpkgs directly, through the web - see, e.g., http://catamaran.labs.cs.uu.nl/dist/nixpkgs-0.8/. All you have to do is associate `/nix/bin/nix-install-package' with `application/nix-package' (or the extension `.nixpkg'), and clicking on a package link will cause it to be installed, with all appropriate dependencies. If you just want to install some specific application, this is easier than subscribing to a channel. * `nix-store -r PATHS' now builds all the derivations PATHS in parallel. Previously it did them sequentially (though exploiting possible parallelism between subderivations). This is nice for build farms. * `nix-channel' has new operations `--list' and `--remove'. * New ways of installing components into user environments: - Copy from another user environment: $ nix-env -i --from-profile .../other-profile firefox - Install a store derivation directly (bypassing the Nix expression language entirely): $ nix-env -i /nix/store/z58v41v21xd3...-aterm-2.3.1.drv (This is used to implement `nix-install-package', which is therefore immune to evolution in the Nix expression language.) - Install an already built store path directly: $ nix-env -i /nix/store/hsyj5pbn0d9i...-aterm-2.3.1 - Install the result of a Nix expression specified as a command-line argument: $ nix-env -f .../i686-linux.nix -i -E 'x: x.firefoxWrapper' The difference with the normal installation mode is that `-E' does not use the `name' attributes of derivations. Therefore, this can be used to disambiguate multiple derivations with the same name. * A hash of the contents of a store path is now stored in the database after a succesful build. This allows you to check whether store paths have been tampered with: `nix-store --verify --check-contents'. * Implemented a concurrent garbage collector. It is now always safe to run the garbage collector, even if other Nix operations are happening simultaneously. However, there can still be GC races if you use `nix-instantiate' and `nix-store -r' directly to build things. To prevent races, use the `--add-root' flag of those commands. * The garbage collector now finally deletes paths in the right order (i.e., topologically sorted under the `references' relation), thus making it safe to interrupt the collector without risking a store that violates the closure invariant. * Likewise, the substitute mechanism now downloads files in the right order, thus preserving the closure invariant at all times. * The result of `nix-build' is now registered as a root of the garbage collector. If the `./result' link is deleted, the GC root disappears automatically. * The behaviour of the garbage collector can be changed globally by setting options in `/nix/etc/nix/nix.conf'. - `gc-keep-derivations' specifies whether deriver links should be followed when searching for live paths. - `gc-keep-outputs' specifies whether outputs of derivations should be followed when searching for live paths. - `env-keep-derivations' specifies whether user environments should store the paths of derivations when they are added (thus keeping the derivations alive). * New `nix-env' query flags `--drv-path' and `--out-path'. * `fetchurl' allows SHA-1 and SHA-256 in addition to MD5. Just use `sha1 = ' or `sha256 = ' instead of `md5 = '. Of course, they're all unsafe, really ;-) Version 0.7 * Binary patching. When upgrading components using pre-built binaries (through nix-pull / nix-channel), Nix can automatically download and apply binary patches to already installed components instead of full downloads. Patching is "smart": if there is a *sequence* of patches to an installed component, Nix will use it. Patches are currently generated automatically between Nixpkgs (pre-)releases. * Simplifications to the substitute mechanism. * Nix-pull now stores downloaded manifests in /nix/var/nix/manifests. * Metadata on files in the Nix store is canonicalised after builds: the last-modified timestamp is set to 0 (00:00:00 1/1/1970), the mode is set to 0444 or 0555 (readable and possibly executable by all; setuid/setgid bits are dropped), and the group is set to the default. This ensures that the result of a build and an installation through a substitute is the same; and that timestamp dependencies are revealed. Version 0.6 Major changes include the following: * Rewrite of the normalisation engine. * Multiple builds can now be performed in parallel (option `-j'). * Distributed builds. Nix can now call a shell script to forward builds to Nix installations on remote machines, which may or may not be of the same platform type. * Option `--fallback' allows recovery from broken substitutes. * Option `--keep-going' causes building of other (unaffected) derivations to continue if one failed. * Improvements to the garbage collector (i.e., it should actually work now). * Setuid Nix installations allow a Nix store to be shared among multiple users. * Substitute registration is much faster now. * A utility `nix-build' to build a Nix expression and create a symlink to the result int the current directory; useful for testing Nix derivations. * Manual updates. * `nix-env' changes: * Derivations for other platforms are filtered out (which can be overriden using `--system-filter'). * `--install' by default now uninstall previous derivations with the same name. * `--upgrade' allows upgrading to a specific version. * New operation `--delete-generations' to remove profile generations (necessary for effective garbage collection). * Nicer output (sorted, columnised). * More sensible verbosity levels all around (builder output is now shown always, unless `-Q' is given). * Nix expression language changes: * New language construct: `with E1; E2' brings all attributes defined in the attribute set E1 in scope in E2. * Added a `map' function. * Various new operators (e.g., string concatenation). * Expression evaluation is much faster. * An Emacs mode for editing Nix expressions (with syntax highlighting and indentation) has been added. * Many bug fixes. Version 0.5 and earlier Please refer to the Subversion commit log messages.