This removes confusing documentation. It's better to remove doc than add implementation, because Nix 1.12 will surely have new GC interface anyway.
Fixes https://github.com/NixOS/nix/issues/641
While trying to understand garbage collection it was not immediately
clear that only the runtime dependency closure of output paths
would be kept (instead of the build-time dependency closure).
This commit attempts to clarify this by expanding some of the
glossary definitions and extending the Garbage Collection
section.
The overhead of sandbox builds is a problem on NixOS (since building a
NixOS configuration involves a lot of small derivations) but not for
typical non-NixOS use cases. So outside of NixOS we can enable it.
Issue #179.
builtins.path allows specifying the name of a path (which makes paths
with store-illegal names now addable), allows adding paths with flat
instead of recursive hashes, allows specifying a filter (so is a
generalization of filterSource), and allows specifying an expected
hash (enabling safe path adding in pure mode).
Instead, if a fixed-output derivation produces has an incorrect output
hash, we now unconditionally move the outputs to the path
corresponding with the actual hash and register it as valid. Thus,
after correcting the hash in the Nix expression (e.g. in a fetchurl
call), the fixed-output derivation doesn't have to be built again.
It would still be good to have a command for reporting the actual hash
of a fixed-output derivation (instead of throwing an error), but
"nix-build --hash" didn't do that.
Following discussion with Shea and Graham. It's a big enough change
from the last release. Also, from a semver perspective, 2.0 makes more
sense because we did remove some interfaces (like nix-pull/nix-push).
The name had become a misnomer since it's not only for substitution
from binary caches, but when adding/copying any
(non-content-addressed) path to a store.
Nix can now automatically run the garbage collector during builds or
while adding paths to the store. The option "min-free = <bytes>"
specifies that Nix should run the garbage collector whenever free
space in the Nix store drops below <bytes>. It will then delete
garbage until "max-free" bytes are available.
Garbage collection during builds is asynchronous; running builds are
not paused and new builds are not blocked. However, there also is a
synchronous GC run prior to the first build/substitution.
Currently, no old GC roots are deleted (as in "nix-collect-garbage
-d").
In particular, drop the "build-" and "gc-" prefixes which are
pointless. So now you can say
nix build --no-sandbox
instead of
nix build --no-build-use-sandbox
This removes the file nix-mode.el from Nix. The file is now available within the
repository https://github.com/NixOS/nix-mode.
Fixes#662Fixes#1040Fixes#1054Fixes#1055Closes#1119Fixes#1419
NOTE: all of the above should be fixed within NixOS/nix-mode. If one of those
hasn’t please reopen within NixOS/nix-mode and not within NixOS/nix.
This allows builds to call setuid binaries. This was previously
possible until we started using seccomp. Turns out that seccomp by
default disallows processes from acquiring new privileges. Generally,
any use of setuid binaries (except those created by the builder
itself) is by definition impure, but some people were relying on this
ability for certain tests.
Example:
$ nix build '(with import <nixpkgs> {}; runCommand "foo" {} "/run/wrappers/bin/ping -c 1 8.8.8.8; exit 1")' --no-allow-new-privileges
builder for ‘/nix/store/j0nd8kv85hd6r4kxgnwzvr0k65ykf6fv-foo.drv’ failed with exit code 1; last 2 log lines:
cannot raise the capability into the Ambient set
: Operation not permitted
$ nix build '(with import <nixpkgs> {}; runCommand "foo" {} "/run/wrappers/bin/ping -c 1 8.8.8.8; exit 1")' --allow-new-privileges
builder for ‘/nix/store/j0nd8kv85hd6r4kxgnwzvr0k65ykf6fv-foo.drv’ failed with exit code 1; last 6 log lines:
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=46 time=15.2 ms
Fixes#1429.
This is to simplify remote build configuration. These environment
variables predate nix.conf.
The build hook now has a sensible default (namely build-remote).
The current load is kept in the Nix state directory now.
This portion of the quick start guide may lead to confusion for
newcomers to Nix. This change clarifies the example to one that can be
copied in its entirety.
This allows various Store implementations to provide different ways to
get build logs. For example, BinaryCacheStore can get the build logs
from the binary cache.
Also, remove the log-servers option since we can use substituters for
this.
"build-max-jobs" and the "-j" option can now be set to "auto" to use
the number of CPUs in the system. (Unlike build-cores, it doesn't use
0 to imply auto-configuration, because a) magic values are a bad idea
in general; b) 0 is a legitimate value used to disable local
building.)
Fixes#1198.
The current behaviour modifies the first writeable file from amongst
.bash_profile, .bash_login and .profile. So .bash_profile (if it is
writable) would be modified even if a user has already sourced nix.sh
in, say, .profile.
This commit introduces a new environment variable,
NIX_INSTALLER_NO_MODIFY_PROFILE. If this is set during installation,
then the modifications are unconditionally skipped.
This is useful for users who have a manually curated set of dotfiles
that they are porting to a new machine. In such scenarios, nix.sh is
already sourced at a place where the user prefers. Without this
change, the nix installer would insist on modifying .bash_profile if
it exists.
This commit also add documentations for both the current behaviour and
the new override.
For example, you can now set
build-sandbox-paths = /dev/nvidiactl?
to specify that /dev/nvidiactl should only be mounted in the sandbox
if it exists in the host filesystem. This is useful e.g. for EC2
images that should support both CUDA and non-CUDA instances.
It's a slight misnomer now because it actually limits *all* downloads,
not just binary cache lookups.
Also add a "enable-http2" option to allow disabling use of HTTP/2
(enabled by default).
Once upon a time, I wrote my bachelors thesis about functional
deployment mechanisms.
I had to evaluate several szenarios where package management and
deployment were relevant. One szenario was to do distributed builds
over several machines.
I told myself: Weee, nix can do this! And with nix, this is actually
save, as you do not have side effects when building!
So I started. I use a cloud to set up four virtual machines where I
wanted to do the build. A fifth machine was used as master to distribute
the builds. All was good.
I created the necessary SSH keys, made sure every machine was reachable
by the master and configured the build in my remotes.conf.
When I started to try to build weechat from source, the build failed. It
failed, telling me
error: unable to start any build; either increase ‘--max-jobs’ or enable distributed builds
And I started to dig around. I digged long and good. But I wasn't able
to find the issue.
I double and triple checked my environment variables, my settings, the
SSH key and everything.
I reached out to fellow Nixers by asking on the nixos IRC channel. And I
got help. But we weren't able to find the issue, either.
So I became frustrated. I re-did all the environment variables.
And suddenly,... it worked! What did I change? Well... I made the
environment variables which contained pathes contain absolute pathes
rather than relatives.
And because I like to share my knowledge, this should be put into the
documentation, so others do not bang their heads against the wall
because something is not documented somewhere.
Docbook XSL got updated to version 1.79.1 in NixOS/nixpkgs@fb893a8 and
we're still referring to the hardcoded previous version.
So instead of just updating this to 1.79.1 we're going to use "current"
in the hope that this won't happen again.
I have tested this by building the manual under Nix(OS) but I haven't
tested this in a non-Nix environment, so I'm not sure whether this could
have implications.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Cc: @edolstra
The existing "nix-build" examples were failing:
error: cannot auto-call a function that has an argument without a default value (‘system’)
Thanks to @groxxda on irc for pointing out the fix!
Updated to completely remove unneeded path argument, suggested by @joachifm
Updated to remove other occurences of `all-packages.nix` from files as
suggested by @domenkozar
Some benchmarking suggested this as a good value. Running
$ benchmark -f ... -t 25 -- sh -c 'rm -f /nix/var/nix/binary-cache*; nix-store -r /nix/store/x5z8a2yvz8h6ccmhwrwrp9igg03575jg-nixos-15.09.git.5fd87e1M.drv --dry-run --option binary-caches-parallel-connections <N>'
gave the following mean elapsed times for these values of N:
N=10: 3.3541
N=20: 2.9320
N=25: 2.6690
N=30: 2.9417
N=50: 3.2021
N=100: 3.5718
N=150: 4.2079
Memory usage is also reduced (N=150 used 186 MB, N=25 only 68 MB).
Closes#708.
- rename options but leav old names as lower-priority aliases,
also "-dirs" -> "-paths" to get closer to the meaning
- update docs to reflect the new names (old aliases are not documented),
including a new file with release notes
- tests need an update after corresponding changes to nixpkgs
- __noChroot is left as it is (after discussion on the PR)
Passing "--option build-repeat <N>" will cause every build to be
repeated N times. If the build output differs between any round, the
build is rejected, and the output paths are not registered as
valid. This is primarily useful to verify build determinism. (We
already had a --check option to repeat a previously succeeded
build. However, with --check, non-deterministic builds are registered
in the DB. Preventing that is useful for Hydra to ensure that
non-deterministic builds don't end up getting published at all.)
This allows overriding the name component of the resulting Nix store
path, which is necessary if the base name of the URI contains
"illegal" characters.
This allows nix-prefetch-url to prefetch the output of fetchzip and
its wrappers (like fetchFromGitHub). For example:
$ nix-prefetch-url --unpack https://github.com/NixOS/patchelf/archive/0.8.tar.gz
or from a Nix expression:
$ nix-prefetch-url -A nix-repl.src
In the latter case, --unpack can be omitted because nix-repl.src is a
fetchFromGitHub derivation and thus has "outputHashMode" set to
"recursive".
For example,
$ nix-prefetch-url -A hello.src
will prefetch the file specified by the fetchurl call in the attribute
‘hello.src’ from the Nix expression in the current directory. This
differs from ‘nix-build -A hello.src’ in that it doesn't verify the
hash.
You can also specify a path to the Nix expression:
$ nix-prefetch-url ~/Dev/nixpkgs -A hello.src
List elements (typically used in ‘patches’ attributes) also work:
$ nix-prefetch-url -A portmidi.patches.0
This hook can be used to set system-specific per-derivation build
settings that don't fit into the derivation model and are too complex or
volatile to be hard-coded into nix. Currently, the pre-build hook can
only add chroot dirs/files through the interface, but it also has full
access to the chroot root.
The specific use case for this is systems where the operating system ABI
is more complex than just the kernel-support system calls. For example,
on OS X there is a set of system-provided frameworks that can reliably
be accessed by any program linked to them, no matter the version the
program is running on. Unfortunately, those frameworks do not
necessarily live in the same locations on each version of OS X, nor do
their dependencies, and thus nix needs to know the specific version of
OS X currently running in order to make those frameworks available. The
pre-build hook is a perfect mechanism for doing just that.
This hook can be used to set system specific per-derivation build
settings that don't fit into the derivation model and are too complex or
volatile to be hard-coded into nix. Currently, the pre-build hook can
only add chroot dirs/files.
The specific use case for this is systems where the operating system ABI
is more complex than just the kernel-supported system calls. For
example, on OS X there is a set of system-provided frameworks that can
reliably be accessed by any program linked to them, no matter the
version the program is running on. Unfortunately, those frameworks do
not necessarily live in the same locations on each version of OS X, nor
do their dependencies, and thus nix needs to know the specific version
of OS X currently running in order to make those frameworks available.
The pre-build hook is a perfect mechanism for doing just that.
If ‘build-use-chroot’ is set to ‘true’, fixed-output derivations are
now also chrooted. However, unlike normal derivations, they don't get
a private network namespace, so they can still access the
network. Also, the use of the ‘__noChroot’ derivation attribute is
no longer allowed.
Setting ‘build-use-chroot’ to ‘relaxed’ gives the old behaviour.
If ‘--option restrict-eval true’ is given, the evaluator will throw an
exception if an attempt is made to access any file outside of the Nix
search path. This is primarily intended for Hydra, where we don't want
people doing ‘builtins.readFile ~/.ssh/id_dsa’ or stuff like that.
‘--run’ is like ‘--command’, except that it runs the command in a
non-interactive shell. This is important if you do things like:
$ nix-shell --command make
Hitting Ctrl-C while make is running drops you into the interactive
Nix shell, which is probably not what you want. So you can now do
$ nix-shell --run make
instead.
'... another level of indirection not shown in the figure above ...'
but in the 'user-environments.png' figure there is '~/.nix-profile'.
the figure was updated with the commit: f982df3 on Mar 16, 2005.
‘trusted-users’ is a list of users and groups that have elevated
rights, such as the ability to specify binary caches. It defaults to
‘root’. A typical value would be ‘@wheel’ to specify all users in the
wheel group.
‘allowed-users’ is a list of users and groups that are allowed to
connect to the daemon. It defaults to ‘*’. A typical value would be
‘@users’ to specify the ‘users’ group.
If a build log is not available locally, then ‘nix-store -l’ will now
try to download it from the servers listed in the ‘log-servers’ option
in nix.conf. For instance, if you have:
log-servers = http://hydra.nixos.org/log
then it will try to get logs from http://hydra.nixos.org/log/<base
name of the store path>. So you can do things like:
$ nix-store -l $(which xterm)
and get a log even if xterm wasn't built locally.
The option '--delete-generations Nd' deletes all generations older than N
days. However, most likely the user does not want to delete the
generation that was active N days ago.
For example, say that you have these 3 generations:
1: <30 days ago>
2: <15 days ago>
3: <1 hour ago>
If you do --delete-generations 7d (say, as part of a cron job), most
likely you still want to keep generation 2, i.e. the generation that was
active 7 days ago (and for most of the past 7 days, in fact).
This patch fixes this issue. Note that this also affects
'nix-collect-garbage --delete-older-than Nd'.
Thanks to @roconnor for noticing the issue!
Samuel Dionne-Riel
Jonas Chevalier
Linus Heckemann
Scott Olson
Bob van der Linden