forked from lix-project/lix
834 lines
27 KiB
Markdown
834 lines
27 KiB
Markdown
# Name
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`nix-store` - manipulate or query the Nix store
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# Synopsis
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`nix-store` *operation* [*options…*] [*arguments…*]
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[`--option` *name* *value*]
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[`--add-root` *path*]
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# Description
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The command `nix-store` performs primitive operations on the Nix store.
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You generally do not need to run this command manually.
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`nix-store` takes exactly one *operation* flag which indicates the
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subcommand to be performed. These are documented below.
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# Common options
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This section lists the options that are common to all operations. These
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options are allowed for every subcommand, though they may not always
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have an effect.
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- `--add-root` *path*
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Causes the result of a realisation (`--realise` and
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`--force-realise`) to be registered as a root of the garbage
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collector. *path* will be created as a symlink to the resulting
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store path. In addition, a uniquely named symlink to *path* will
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be created in `/nix/var/nix/gcroots/auto/`. For instance,
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```console
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$ nix-store --add-root /home/eelco/bla/result -r ...
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$ ls -l /nix/var/nix/gcroots/auto
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lrwxrwxrwx 1 ... 2005-03-13 21:10 dn54lcypm8f8... -> /home/eelco/bla/result
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$ ls -l /home/eelco/bla/result
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lrwxrwxrwx 1 ... 2005-03-13 21:10 /home/eelco/bla/result -> /nix/store/1r11343n6qd4...-f-spot-0.0.10
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```
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Thus, when `/home/eelco/bla/result` is removed, the GC root in the
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`auto` directory becomes a dangling symlink and will be ignored by
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the collector.
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> **Warning**
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>
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> Note that it is not possible to move or rename GC roots, since
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> the symlink in the `auto` directory will still point to the old
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> location.
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If there are multiple results, then multiple symlinks will be
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created by sequentially numbering symlinks beyond the first one
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(e.g., `foo`, `foo-2`, `foo-3`, and so on).
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# Operation `--realise`
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## Synopsis
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`nix-store` {`--realise` | `-r`} *paths…* [`--dry-run`]
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## Description
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The operation `--realise` essentially “builds” the specified store
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paths. Realisation is a somewhat overloaded term:
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- If the store path is a *derivation*, realisation ensures that the
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output paths of the derivation are [valid](../glossary.md) (i.e.,
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the output path and its closure exist in the file system). This
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can be done in several ways. First, it is possible that the
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outputs are already valid, in which case we are done
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immediately. Otherwise, there may be [substitutes](../glossary.md)
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that produce the outputs (e.g., by downloading them). Finally, the
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outputs can be produced by performing the build action described
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by the derivation.
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- If the store path is not a derivation, realisation ensures that the
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specified path is valid (i.e., it and its closure exist in the file
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system). If the path is already valid, we are done immediately.
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Otherwise, the path and any missing paths in its closure may be
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produced through substitutes. If there are no (successful)
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subsitutes, realisation fails.
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The output path of each derivation is printed on standard output. (For
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non-derivations argument, the argument itself is printed.)
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The following flags are available:
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- `--dry-run`
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Print on standard error a description of what packages would be
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built or downloaded, without actually performing the operation.
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- `--ignore-unknown`
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If a non-derivation path does not have a substitute, then silently
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ignore it.
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- `--check`
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This option allows you to check whether a derivation is
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deterministic. It rebuilds the specified derivation and checks
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whether the result is bitwise-identical with the existing outputs,
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printing an error if that’s not the case. The outputs of the
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specified derivation must already exist. When used with `-K`, if an
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output path is not identical to the corresponding output from the
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previous build, the new output path is left in
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`/nix/store/name.check.`
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See also the `build-repeat` configuration option, which repeats a
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derivation a number of times and prevents its outputs from being
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registered as “valid” in the Nix store unless they are identical.
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Special exit codes:
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- `100`
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Generic build failure, the builder process returned with a non-zero
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exit code.
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- `101`
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Build timeout, the build was aborted because it did not complete
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within the specified `timeout`.
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- `102`
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Hash mismatch, the build output was rejected because it does not
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match the [`outputHash` attribute of the
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derivation](../expressions/advanced-attributes.md).
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- `104`
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Not deterministic, the build succeeded in check mode but the
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resulting output is not binary reproducable.
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With the `--keep-going` flag it's possible for multiple failures to
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occur, in this case the 1xx status codes are or combined using binary
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or.
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1100100
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^^^^
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|||`- timeout
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||`-- output hash mismatch
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|`--- build failure
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`---- not deterministic
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## Examples
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This operation is typically used to build store derivations produced by
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[`nix-instantiate`](nix-instantiate.md):
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```console
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$ nix-store -r $(nix-instantiate ./test.nix)
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/nix/store/31axcgrlbfsxzmfff1gyj1bf62hvkby2-aterm-2.3.1
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```
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This is essentially what [`nix-build`](nix-build.md) does.
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To test whether a previously-built derivation is deterministic:
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```console
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$ nix-build '<nixpkgs>' -A hello --check -K
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```
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# Operation `--serve`
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## Synopsis
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`nix-store` `--serve` [`--write`]
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## Description
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The operation `--serve` provides access to the Nix store over stdin and
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stdout, and is intended to be used as a means of providing Nix store
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access to a restricted ssh user.
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The following flags are available:
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- `--write`
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Allow the connected client to request the realization of
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derivations. In effect, this can be used to make the host act as a
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remote builder.
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## Examples
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To turn a host into a build server, the `authorized_keys` file can be
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used to provide build access to a given SSH public key:
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```console
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$ cat <<EOF >>/root/.ssh/authorized_keys
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command="nice -n20 nix-store --serve --write" ssh-rsa AAAAB3NzaC1yc2EAAAA...
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EOF
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```
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# Operation `--gc`
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## Synopsis
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`nix-store` `--gc` [`--print-roots` | `--print-live` | `--print-dead`] [`--max-freed` *bytes*]
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## Description
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Without additional flags, the operation `--gc` performs a garbage
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collection on the Nix store. That is, all paths in the Nix store not
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reachable via file system references from a set of “roots”, are deleted.
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The following suboperations may be specified:
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- `--print-roots`
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This operation prints on standard output the set of roots used by
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the garbage collector.
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- `--print-live`
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This operation prints on standard output the set of “live” store
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paths, which are all the store paths reachable from the roots. Live
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paths should never be deleted, since that would break consistency —
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it would become possible that applications are installed that
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reference things that are no longer present in the store.
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- `--print-dead`
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This operation prints out on standard output the set of “dead” store
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paths, which is just the opposite of the set of live paths: any path
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in the store that is not live (with respect to the roots) is dead.
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By default, all unreachable paths are deleted. The following options
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control what gets deleted and in what order:
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- `--max-freed` *bytes*
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Keep deleting paths until at least *bytes* bytes have been deleted,
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then stop. The argument *bytes* can be followed by the
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multiplicative suffix `K`, `M`, `G` or `T`, denoting KiB, MiB, GiB
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or TiB units.
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The behaviour of the collector is also influenced by the
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`keep-outputs` and `keep-derivations` settings in the Nix
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configuration file.
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By default, the collector prints the total number of freed bytes when it
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finishes (or when it is interrupted). With `--print-dead`, it prints the
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number of bytes that would be freed.
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## Examples
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To delete all unreachable paths, just do:
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```console
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$ nix-store --gc
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deleting `/nix/store/kq82idx6g0nyzsp2s14gfsc38npai7lf-cairo-1.0.4.tar.gz.drv'
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...
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8825586 bytes freed (8.42 MiB)
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```
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To delete at least 100 MiBs of unreachable paths:
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```console
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$ nix-store --gc --max-freed $((100 * 1024 * 1024))
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```
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# Operation `--delete`
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## Synopsis
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`nix-store` `--delete` [`--ignore-liveness`] *paths…*
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## Description
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The operation `--delete` deletes the store paths *paths* from the Nix
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store, but only if it is safe to do so; that is, when the path is not
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reachable from a root of the garbage collector. This means that you can
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only delete paths that would also be deleted by `nix-store --gc`. Thus,
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`--delete` is a more targeted version of `--gc`.
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With the option `--ignore-liveness`, reachability from the roots is
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ignored. However, the path still won’t be deleted if there are other
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paths in the store that refer to it (i.e., depend on it).
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## Example
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```console
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$ nix-store --delete /nix/store/zq0h41l75vlb4z45kzgjjmsjxvcv1qk7-mesa-6.4
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0 bytes freed (0.00 MiB)
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error: cannot delete path `/nix/store/zq0h41l75vlb4z45kzgjjmsjxvcv1qk7-mesa-6.4' since it is still alive
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```
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# Operation `--query`
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## Synopsis
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`nix-store` {`--query` | `-q`}
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{`--outputs` | `--requisites` | `-R` | `--references` |
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`--referrers` | `--referrers-closure` | `--deriver` | `-d` |
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`--graph` | `--tree` | `--binding` *name* | `-b` *name* | `--hash` |
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`--size` | `--roots`}
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[`--use-output`] [`-u`] [`--force-realise`] [`-f`]
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*paths…*
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## Description
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The operation `--query` displays various bits of information about the
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store paths . The queries are described below. At most one query can be
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specified. The default query is `--outputs`.
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The paths *paths* may also be symlinks from outside of the Nix store, to
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the Nix store. In that case, the query is applied to the target of the
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symlink.
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## Common query options
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- `--use-output`; `-u`
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For each argument to the query that is a store derivation, apply the
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query to the output path of the derivation instead.
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- `--force-realise`; `-f`
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Realise each argument to the query first (see [`nix-store
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--realise`](#operation---realise)).
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## Queries
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- `--outputs`
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Prints out the [output paths](../glossary.md) of the store
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derivations *paths*. These are the paths that will be produced when
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the derivation is built.
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- `--requisites`; `-R`
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Prints out the [closure](../glossary.md) of the store path *paths*.
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This query has one option:
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- `--include-outputs`
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Also include the output path of store derivations, and their
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closures.
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This query can be used to implement various kinds of deployment. A
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*source deployment* is obtained by distributing the closure of a
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store derivation. A *binary deployment* is obtained by distributing
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the closure of an output path. A *cache deployment* (combined
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source/binary deployment, including binaries of build-time-only
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dependencies) is obtained by distributing the closure of a store
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derivation and specifying the option `--include-outputs`.
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- `--references`
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Prints the set of [references](../glossary.md) of the store paths
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*paths*, that is, their immediate dependencies. (For *all*
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dependencies, use `--requisites`.)
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- `--referrers`
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Prints the set of *referrers* of the store paths *paths*, that is,
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the store paths currently existing in the Nix store that refer to
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one of *paths*. Note that contrary to the references, the set of
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referrers is not constant; it can change as store paths are added or
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removed.
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- `--referrers-closure`
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Prints the closure of the set of store paths *paths* under the
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referrers relation; that is, all store paths that directly or
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indirectly refer to one of *paths*. These are all the path currently
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in the Nix store that are dependent on *paths*.
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- `--deriver`; `-d`
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Prints the [deriver](../glossary.md) of the store paths *paths*. If
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the path has no deriver (e.g., if it is a source file), or if the
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deriver is not known (e.g., in the case of a binary-only
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deployment), the string `unknown-deriver` is printed.
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- `--graph`
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Prints the references graph of the store paths *paths* in the format
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of the `dot` tool of AT\&T's [Graphviz
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package](http://www.graphviz.org/). This can be used to visualise
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dependency graphs. To obtain a build-time dependency graph, apply
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this to a store derivation. To obtain a runtime dependency graph,
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apply it to an output path.
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- `--tree`
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Prints the references graph of the store paths *paths* as a nested
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ASCII tree. References are ordered by descending closure size; this
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tends to flatten the tree, making it more readable. The query only
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recurses into a store path when it is first encountered; this
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prevents a blowup of the tree representation of the graph.
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- `--graphml`
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Prints the references graph of the store paths *paths* in the
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[GraphML](http://graphml.graphdrawing.org/) file format. This can be
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used to visualise dependency graphs. To obtain a build-time
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dependency graph, apply this to a store derivation. To obtain a
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runtime dependency graph, apply it to an output path.
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- `--binding` *name*; `-b` *name*
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Prints the value of the attribute *name* (i.e., environment
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variable) of the store derivations *paths*. It is an error for a
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derivation to not have the specified attribute.
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- `--hash`
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Prints the SHA-256 hash of the contents of the store paths *paths*
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(that is, the hash of the output of `nix-store --dump` on the given
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paths). Since the hash is stored in the Nix database, this is a fast
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operation.
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- `--size`
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Prints the size in bytes of the contents of the store paths *paths*
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— to be precise, the size of the output of `nix-store --dump` on
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the given paths. Note that the actual disk space required by the
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store paths may be higher, especially on filesystems with large
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cluster sizes.
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- `--roots`
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Prints the garbage collector roots that point, directly or
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indirectly, at the store paths *paths*.
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## Examples
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Print the closure (runtime dependencies) of the `svn` program in the
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current user environment:
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```console
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$ nix-store -qR $(which svn)
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/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
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/nix/store/9lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4
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...
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```
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Print the build-time dependencies of `svn`:
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```console
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$ nix-store -qR $(nix-store -qd $(which svn))
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/nix/store/02iizgn86m42q905rddvg4ja975bk2i4-grep-2.5.1.tar.bz2.drv
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/nix/store/07a2bzxmzwz5hp58nf03pahrv2ygwgs3-gcc-wrapper.sh
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/nix/store/0ma7c9wsbaxahwwl04gbw3fcd806ski4-glibc-2.3.4.drv
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... lots of other paths ...
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```
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The difference with the previous example is that we ask the closure of
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the derivation (`-qd`), not the closure of the output path that contains
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`svn`.
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Show the build-time dependencies as a tree:
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```console
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$ nix-store -q --tree $(nix-store -qd $(which svn))
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/nix/store/7i5082kfb6yjbqdbiwdhhza0am2xvh6c-subversion-1.1.4.drv
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+---/nix/store/d8afh10z72n8l1cr5w42366abiblgn54-builder.sh
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+---/nix/store/fmzxmpjx2lh849ph0l36snfj9zdibw67-bash-3.0.drv
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| +---/nix/store/570hmhmx3v57605cqg9yfvvyh0nnb8k8-bash
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| +---/nix/store/p3srsbd8dx44v2pg6nbnszab5mcwx03v-builder.sh
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...
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```
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Show all paths that depend on the same OpenSSL library as `svn`:
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```console
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$ nix-store -q --referrers $(nix-store -q --binding openssl $(nix-store -qd $(which svn)))
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/nix/store/23ny9l9wixx21632y2wi4p585qhva1q8-sylpheed-1.0.0
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/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
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/nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3
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/nix/store/l51240xqsgg8a7yrbqdx1rfzyv6l26fx-lynx-2.8.5
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```
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Show all paths that directly or indirectly depend on the Glibc (C
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library) used by `svn`:
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```console
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$ nix-store -q --referrers-closure $(ldd $(which svn) | grep /libc.so | awk '{print $3}')
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/nix/store/034a6h4vpz9kds5r6kzb9lhh81mscw43-libgnomeprintui-2.8.2
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/nix/store/15l3yi0d45prm7a82pcrknxdh6nzmxza-gawk-3.1.4
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...
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```
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Note that `ldd` is a command that prints out the dynamic libraries used
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by an ELF executable.
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Make a picture of the runtime dependency graph of the current user
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environment:
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```console
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$ nix-store -q --graph ~/.nix-profile | dot -Tps > graph.ps
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$ gv graph.ps
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```
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Show every garbage collector root that points to a store path that
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depends on `svn`:
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```console
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$ nix-store -q --roots $(which svn)
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/nix/var/nix/profiles/default-81-link
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/nix/var/nix/profiles/default-82-link
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/nix/var/nix/profiles/per-user/eelco/profile-97-link
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```
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# Operation `--add`
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||
## Synopsis
|
||
|
||
`nix-store` `--add` *paths…*
|
||
|
||
## Description
|
||
|
||
The operation `--add` adds the specified paths to the Nix store. It
|
||
prints the resulting paths in the Nix store on standard output.
|
||
|
||
## Example
|
||
|
||
```console
|
||
$ nix-store --add ./foo.c
|
||
/nix/store/m7lrha58ph6rcnv109yzx1nk1cj7k7zf-foo.c
|
||
```
|
||
|
||
# Operation `--add-fixed`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--add-fixed` [`--recursive`] *algorithm* *paths…*
|
||
|
||
## Description
|
||
|
||
The operation `--add-fixed` adds the specified paths to the Nix store.
|
||
Unlike `--add` paths are registered using the specified hashing
|
||
algorithm, resulting in the same output path as a fixed-output
|
||
derivation. This can be used for sources that are not available from a
|
||
public url or broke since the download expression was written.
|
||
|
||
This operation has the following options:
|
||
|
||
- `--recursive`
|
||
Use recursive instead of flat hashing mode, used when adding
|
||
directories to the store.
|
||
|
||
## Example
|
||
|
||
```console
|
||
$ nix-store --add-fixed sha256 ./hello-2.10.tar.gz
|
||
/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz
|
||
```
|
||
|
||
# Operation `--verify`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--verify` [`--check-contents`] [`--repair`]
|
||
|
||
## Description
|
||
|
||
The operation `--verify` verifies the internal consistency of the Nix
|
||
database, and the consistency between the Nix database and the Nix
|
||
store. Any inconsistencies encountered are automatically repaired.
|
||
Inconsistencies are generally the result of the Nix store or database
|
||
being modified by non-Nix tools, or of bugs in Nix itself.
|
||
|
||
This operation has the following options:
|
||
|
||
- `--check-contents`
|
||
Checks that the contents of every valid store path has not been
|
||
altered by computing a SHA-256 hash of the contents and comparing it
|
||
with the hash stored in the Nix database at build time. Paths that
|
||
have been modified are printed out. For large stores,
|
||
`--check-contents` is obviously quite slow.
|
||
|
||
- `--repair`
|
||
If any valid path is missing from the store, or (if
|
||
`--check-contents` is given) the contents of a valid path has been
|
||
modified, then try to repair the path by redownloading it. See
|
||
`nix-store --repair-path` for details.
|
||
|
||
# Operation `--verify-path`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--verify-path` *paths…*
|
||
|
||
## Description
|
||
|
||
The operation `--verify-path` compares the contents of the given store
|
||
paths to their cryptographic hashes stored in Nix’s database. For every
|
||
changed path, it prints a warning message. The exit status is 0 if no
|
||
path has changed, and 1 otherwise.
|
||
|
||
## Example
|
||
|
||
To verify the integrity of the `svn` command and all its dependencies:
|
||
|
||
```console
|
||
$ nix-store --verify-path $(nix-store -qR $(which svn))
|
||
```
|
||
|
||
# Operation `--repair-path`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--repair-path` *paths…*
|
||
|
||
## Description
|
||
|
||
The operation `--repair-path` attempts to “repair” the specified paths
|
||
by redownloading them using the available substituters. If no
|
||
substitutes are available, then repair is not possible.
|
||
|
||
> **Warning**
|
||
>
|
||
> During repair, there is a very small time window during which the old
|
||
> path (if it exists) is moved out of the way and replaced with the new
|
||
> path. If repair is interrupted in between, then the system may be left
|
||
> in a broken state (e.g., if the path contains a critical system
|
||
> component like the GNU C Library).
|
||
|
||
## Example
|
||
|
||
```console
|
||
$ nix-store --verify-path /nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13
|
||
path `/nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13' was modified!
|
||
expected hash `2db57715ae90b7e31ff1f2ecb8c12ec1cc43da920efcbe3b22763f36a1861588',
|
||
got `481c5aa5483ebc97c20457bb8bca24deea56550d3985cda0027f67fe54b808e4'
|
||
|
||
$ nix-store --repair-path /nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13
|
||
fetching path `/nix/store/d7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13'...
|
||
…
|
||
```
|
||
|
||
# Operation `--dump`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--dump` *path*
|
||
|
||
## Description
|
||
|
||
The operation `--dump` produces a NAR (Nix ARchive) file containing the
|
||
contents of the file system tree rooted at *path*. The archive is
|
||
written to standard output.
|
||
|
||
A NAR archive is like a TAR or Zip archive, but it contains only the
|
||
information that Nix considers important. For instance, timestamps are
|
||
elided because all files in the Nix store have their timestamp set to 0
|
||
anyway. Likewise, all permissions are left out except for the execute
|
||
bit, because all files in the Nix store have 444 or 555 permission.
|
||
|
||
Also, a NAR archive is *canonical*, meaning that “equal” paths always
|
||
produce the same NAR archive. For instance, directory entries are
|
||
always sorted so that the actual on-disk order doesn’t influence the
|
||
result. This means that the cryptographic hash of a NAR dump of a
|
||
path is usable as a fingerprint of the contents of the path. Indeed,
|
||
the hashes of store paths stored in Nix’s database (see `nix-store -q
|
||
--hash`) are SHA-256 hashes of the NAR dump of each store path.
|
||
|
||
NAR archives support filenames of unlimited length and 64-bit file
|
||
sizes. They can contain regular files, directories, and symbolic links,
|
||
but not other types of files (such as device nodes).
|
||
|
||
A Nix archive can be unpacked using `nix-store
|
||
--restore`.
|
||
|
||
# Operation `--restore`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--restore` *path*
|
||
|
||
## Description
|
||
|
||
The operation `--restore` unpacks a NAR archive to *path*, which must
|
||
not already exist. The archive is read from standard input.
|
||
|
||
# Operation `--export`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--export` *paths…*
|
||
|
||
## Description
|
||
|
||
The operation `--export` writes a serialisation of the specified store
|
||
paths to standard output in a format that can be imported into another
|
||
Nix store with `nix-store --import`. This is like `nix-store
|
||
--dump`, except that the NAR archive produced by that command doesn’t
|
||
contain the necessary meta-information to allow it to be imported into
|
||
another Nix store (namely, the set of references of the path).
|
||
|
||
This command does not produce a *closure* of the specified paths, so if
|
||
a store path references other store paths that are missing in the target
|
||
Nix store, the import will fail. To copy a whole closure, do something
|
||
like:
|
||
|
||
```console
|
||
$ nix-store --export $(nix-store -qR paths) > out
|
||
```
|
||
|
||
To import the whole closure again, run:
|
||
|
||
```console
|
||
$ nix-store --import < out
|
||
```
|
||
|
||
# Operation `--import`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--import`
|
||
|
||
## Description
|
||
|
||
The operation `--import` reads a serialisation of a set of store paths
|
||
produced by `nix-store --export` from standard input and adds those
|
||
store paths to the Nix store. Paths that already exist in the Nix store
|
||
are ignored. If a path refers to another path that doesn’t exist in the
|
||
Nix store, the import fails.
|
||
|
||
# Operation `--optimise`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--optimise`
|
||
|
||
## Description
|
||
|
||
The operation `--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%. Only
|
||
regular files and symlinks are hard-linked in this manner. Files are
|
||
considered identical when they have the same NAR archive serialisation:
|
||
that is, regular files must have the same contents and permission
|
||
(executable or non-executable), and symlinks must have the same
|
||
contents.
|
||
|
||
After completion, or when the command is interrupted, a report on the
|
||
achieved savings is printed on standard error.
|
||
|
||
Use `-vv` or `-vvv` to get some progress indication.
|
||
|
||
## Example
|
||
|
||
```console
|
||
$ nix-store --optimise
|
||
hashing files in `/nix/store/qhqx7l2f1kmwihc9bnxs7rc159hsxnf3-gcc-4.1.1'
|
||
...
|
||
541838819 bytes (516.74 MiB) freed by hard-linking 54143 files;
|
||
there are 114486 files with equal contents out of 215894 files in total
|
||
```
|
||
|
||
# Operation `--read-log`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` {`--read-log` | `-l`} *paths…*
|
||
|
||
## Description
|
||
|
||
The operation `--read-log` prints the build log of the specified store
|
||
paths on standard output. The build log is whatever the builder of a
|
||
derivation wrote to standard output and standard error. If a store path
|
||
is not a derivation, the deriver of the store path is used.
|
||
|
||
Build logs are kept in `/nix/var/log/nix/drvs`. However, there is no
|
||
guarantee that a build log is available for any particular store path.
|
||
For instance, if the path was downloaded as a pre-built binary through a
|
||
substitute, then the log is unavailable.
|
||
|
||
## Example
|
||
|
||
```console
|
||
$ nix-store -l $(which ktorrent)
|
||
building /nix/store/dhc73pvzpnzxhdgpimsd9sw39di66ph1-ktorrent-2.2.1
|
||
unpacking sources
|
||
unpacking source archive /nix/store/p8n1jpqs27mgkjw07pb5269717nzf5f8-ktorrent-2.2.1.tar.gz
|
||
ktorrent-2.2.1/
|
||
ktorrent-2.2.1/NEWS
|
||
...
|
||
```
|
||
|
||
# Operation `--dump-db`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--dump-db` [*paths…*]
|
||
|
||
## Description
|
||
|
||
The operation `--dump-db` writes a dump of the Nix database to standard
|
||
output. It can be loaded into an empty Nix store using `--load-db`. This
|
||
is useful for making backups and when migrating to different database
|
||
schemas.
|
||
|
||
By default, `--dump-db` will dump the entire Nix database. When one or
|
||
more store paths is passed, only the subset of the Nix database for
|
||
those store paths is dumped. As with `--export`, the user is responsible
|
||
for passing all the store paths for a closure. See `--export` for an
|
||
example.
|
||
|
||
# Operation `--load-db`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--load-db`
|
||
|
||
## Description
|
||
|
||
The operation `--load-db` reads a dump of the Nix database created by
|
||
`--dump-db` from standard input and loads it into the Nix database.
|
||
|
||
# Operation `--print-env`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--print-env` *drvpath*
|
||
|
||
## Description
|
||
|
||
The operation `--print-env` prints out the environment of a derivation
|
||
in a format that can be evaluated by a shell. The command line arguments
|
||
of the builder are placed in the variable `_args`.
|
||
|
||
## Example
|
||
|
||
```console
|
||
$ nix-store --print-env $(nix-instantiate '<nixpkgs>' -A firefox)
|
||
…
|
||
export src; src='/nix/store/plpj7qrwcz94z2psh6fchsi7s8yihc7k-firefox-12.0.source.tar.bz2'
|
||
export stdenv; stdenv='/nix/store/7c8asx3yfrg5dg1gzhzyq2236zfgibnn-stdenv'
|
||
export system; system='x86_64-linux'
|
||
export _args; _args='-e /nix/store/9krlzvny65gdc8s7kpb6lkx8cd02c25c-default-builder.sh'
|
||
```
|
||
|
||
# Operation `--generate-binary-cache-key`
|
||
|
||
## Synopsis
|
||
|
||
`nix-store` `--generate-binary-cache-key` *key-name* *secret-key-file* *public-key-file*
|
||
|
||
## Description
|
||
|
||
This command generates an [Ed25519 key pair](http://ed25519.cr.yp.to/)
|
||
that can be used to create a signed binary cache. It takes three
|
||
mandatory parameters:
|
||
|
||
1. A key name, such as `cache.example.org-1`, that is used to look up
|
||
keys on the client when it verifies signatures. It can be anything,
|
||
but it’s suggested to use the host name of your cache (e.g.
|
||
`cache.example.org`) with a suffix denoting the number of the key
|
||
(to be incremented every time you need to revoke a key).
|
||
|
||
2. The file name where the secret key is to be stored.
|
||
|
||
3. The file name where the public key is to be stored.
|