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R""(
# Examples
* Build the default package from the flake in the current directory:
```console
# nix build
```
* Build and run GNU Hello from the `nixpkgs` flake:
```console
# nix build nixpkgs#hello
# ./result/bin/hello
Hello, world!
```
* Build GNU Hello and Cowsay, leaving two result symlinks:
```console
# nix build nixpkgs#hello nixpkgs#cowsay
# ls -l result*
lrwxrwxrwx 1 … result -> /nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10
lrwxrwxrwx 1 … result-1 -> /nix/store/rkfrm0z6x6jmi7d3gsmma4j53h15mg33-cowsay-3.03+dfsg2
```
* Build a specific output:
```console
# nix build nixpkgs#glibc.dev
# ls -ld ./result-dev
lrwxrwxrwx 1 … ./result-dev -> /nix/store/dkm3gwl0xrx0wrw6zi5x3px3lpgjhlw4-glibc-2.32-dev
```
* Build attribute `build.x86_64-linux` from (non-flake) Nix expression
`release.nix`:
```console
# nix build -f release.nix build.x86_64-linux
```
* Build a NixOS system configuration from a flake, and make a profile
point to the result:
```console
# nix build --profile /nix/var/nix/profiles/system \
~/my-configurations#nixosConfigurations.machine.config.system.build.toplevel
```
(This is essentially what `nixos-rebuild` does.)
* Build an expression specified on the command line:
```console
# nix build --impure --expr \
'with import <nixpkgs> {};
runCommand "foo" {
buildInputs = [ hello ];
}
"hello > $out"'
# cat ./result
Hello, world!
```
Note that `--impure` is needed because we're using `<nixpkgs>`,
which relies on the `$NIX_PATH` environment variable.
* Fetch a store path from the configured substituters, if it doesn't
already exist:
```console
# nix build /nix/store/rkfrm0z6x6jmi7d3gsmma4j53h15mg33-cowsay-3.03+dfsg2
```
# Description
`nix build` builds the specified *installables*. Installables that
resolve to derivations are built (or substituted if possible). Store
path installables are substituted.
Unless `--no-link` is specified, after a successful build, it creates
symlinks to the store paths of the installables. These symlinks have
the prefix `./result` by default; this can be overridden using the
`--out-link` option. Each symlink has a suffix `-<N>-<outname>`, where
*N* is the index of the installable (with the left-most installable
having index 0), and *outname* is the symbolic derivation output name
(e.g. `bin`, `dev` or `lib`). `-<N>` is omitted if *N* = 0, and
`-<outname>` is omitted if *outname* = `out` (denoting the default
output).
)""
|
