diff options
Diffstat (limited to 'doc/manual/src/release-notes/rl-0.11.md')
| -rw-r--r-- | doc/manual/src/release-notes/rl-0.11.md | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/doc/manual/src/release-notes/rl-0.11.md b/doc/manual/src/release-notes/rl-0.11.md new file mode 100644 index 000000000..d2f4d73aa --- /dev/null +++ b/doc/manual/src/release-notes/rl-0.11.md @@ -0,0 +1,167 @@ +# Release 0.11 (2007-12-31) + +Nix 0.11 has many improvements over the previous stable release. The +most important improvement is secure multi-user support. It also +features many usability enhancements and language extensions, many of +them prompted by NixOS, the purely functional Linux distribution based +on Nix. Here is an (incomplete) list: + + - Secure multi-user support. A single Nix store can now be shared + between multiple (possible untrusted) users. This is an important + feature for NixOS, where it allows non-root users to install + software. The old setuid method for sharing a store between multiple + users has been removed. Details for setting up a multi-user store + can be found in the manual. + + - The new command `nix-copy-closure` gives you an easy and efficient + way to exchange software between machines. It copies the missing + parts of the closure of a set of store path to or from a remote + machine via `ssh`. + + - A new kind of string literal: strings between double single-quotes + (`''`) have indentation “intelligently” removed. This allows large + strings (such as shell scripts or configuration file fragments in + NixOS) to cleanly follow the indentation of the surrounding + expression. It also requires much less escaping, since `''` is less + common in most languages than `"`. + + - `nix-env` `--set` modifies the current generation of a profile so + that it contains exactly the specified derivation, and nothing else. + For example, `nix-env -p /nix/var/nix/profiles/browser --set + firefox` lets the profile named `browser` contain just Firefox. + + - `nix-env` now maintains meta-information about installed packages in + profiles. The meta-information is the contents of the `meta` + attribute of derivations, such as `description` or `homepage`. The + command `nix-env -q --xml + --meta` shows all meta-information. + + - `nix-env` now uses the `meta.priority` attribute of derivations to + resolve filename collisions between packages. Lower priority values + denote a higher priority. For instance, the GCC wrapper package and + the Binutils package in Nixpkgs both have a file `bin/ld`, so + previously if you tried to install both you would get a collision. + Now, on the other hand, the GCC wrapper declares a higher priority + than Binutils, so the former’s `bin/ld` is symlinked in the user + environment. + + - `nix-env -i / -u`: instead of breaking package ties by version, + break them by priority and version number. That is, if there are + multiple packages with the same name, then pick the package with the + highest priority, and only use the version if there are multiple + packages with the same priority. + + This makes it possible to mark specific versions/variant in Nixpkgs + more or less desirable than others. A typical example would be a + beta version of some package (e.g., `gcc-4.2.0rc1`) which should not + be installed even though it is the highest version, except when it + is explicitly selected (e.g., `nix-env -i + gcc-4.2.0rc1`). + + - `nix-env --set-flag` allows meta attributes of installed packages to + be modified. There are several attributes that can be usefully + modified, because they affect the behaviour of `nix-env` or the user + environment build script: + + - `meta.priority` can be changed to resolve filename clashes (see + above). + + - `meta.keep` can be set to `true` to prevent the package from + being upgraded or replaced. Useful if you want to hang on to an + older version of a package. + + - `meta.active` can be set to `false` to “disable” the package. + That is, no symlinks will be generated to the files of the + package, but it remains part of the profile (so it won’t be + garbage-collected). Set it back to `true` to re-enable the + package. + + - `nix-env -q` now has a flag `--prebuilt-only` (`-b`) that causes + `nix-env` to show only those derivations whose output is already in + the Nix store or that can be substituted (i.e., downloaded from + somewhere). In other words, it shows the packages that can be + installed “quickly”, i.e., don’t need to be built from source. The + `-b` flag is also available in `nix-env -i` and `nix-env -u` to + filter out derivations for which no pre-built binary is available. + + - The new option `--argstr` (in `nix-env`, `nix-instantiate` and + `nix-build`) is like `--arg`, except that the value is a string. For + example, `--argstr system + i686-linux` is equivalent to `--arg system + \"i686-linux\"` (note that `--argstr` prevents annoying quoting + around shell arguments). + + - `nix-store` has a new operation `--read-log` (`-l`) `paths` that + shows the build log of the given paths. + + - Nix now uses Berkeley DB 4.5. The database is upgraded + automatically, but you should be careful not to use old versions of + Nix that still use Berkeley DB 4.4. + + - The option `--max-silent-time` (corresponding to the configuration + setting `build-max-silent-time`) allows you to set a timeout on + builds — if a build produces no output on `stdout` or `stderr` for + the given number of seconds, it is terminated. This is useful for + recovering automatically from builds that are stuck in an infinite + loop. + + - `nix-channel`: each subscribed channel is its own attribute in the + top-level expression generated for the channel. This allows + disambiguation (e.g. `nix-env + -i -A nixpkgs_unstable.firefox`). + + - The substitutes table has been removed from the database. This makes + operations such as `nix-pull` and `nix-channel --update` much, much + faster. + + - `nix-pull` now supports bzip2-compressed manifests. This speeds up + channels. + + - `nix-prefetch-url` now has a limited form of caching. This is used + by `nix-channel` to prevent unnecessary downloads when the channel + hasn’t changed. + + - `nix-prefetch-url` now by default computes the SHA-256 hash of the + file instead of the MD5 hash. In calls to `fetchurl` you should pass + the `sha256` attribute instead of `md5`. You can pass either a + hexadecimal or a base-32 encoding of the hash. + + - Nix can now perform builds in an automatically generated “chroot”. + This prevents a builder from accessing stuff outside of the Nix + store, and thus helps ensure purity. This is an experimental + feature. + + - The new command `nix-store + --optimise` reduces Nix store disk space usage by finding identical + files in the store and hard-linking them to each other. It typically + reduces the size of the store by something like 25-35%. + + - `~/.nix-defexpr` can now be a directory, in which case the Nix + expressions in that directory are combined into an attribute set, + with the file names used as the names of the attributes. The command + `nix-env + --import` (which set the `~/.nix-defexpr` symlink) is removed. + + - Derivations can specify the new special attribute + `allowedReferences` to enforce that the references in the output of + a derivation are a subset of a declared set of paths. For example, + if `allowedReferences` is an empty list, then the output must not + have any references. This is used in NixOS to check that generated + files such as initial ramdisks for booting Linux don’t have any + dependencies. + + - The new attribute `exportReferencesGraph` allows builders access to + the references graph of their inputs. This is used in NixOS for + tasks such as generating ISO-9660 images that contain a Nix store + populated with the closure of certain paths. + + - Fixed-output derivations (like `fetchurl`) can define the attribute + `impureEnvVars` to allow external environment variables to be passed + to builders. This is used in Nixpkgs to support proxy configuration, + among other things. + + - Several new built-in functions: `builtins.attrNames`, + `builtins.filterSource`, `builtins.isAttrs`, `builtins.isFunction`, + `builtins.listToAttrs`, `builtins.stringLength`, `builtins.sub`, + `builtins.substring`, `throw`, `builtins.trace`, + `builtins.readFile`. |