.\" -*- mode: troff; coding: utf-8 -*-
.TH "nix3-derivation-show" "1" ""
.RS
.PP
\fBWarning\fR 
.br
This program is
\fB\fBexperimental\fR\fR
and its interface is subject to change.
.RE
.SH
Name
.LP
\fCnix derivation show\fR - show the contents of a store derivation
.SH
Synopsis
.LP
\fCnix derivation show\fR [\fIoption\fR\[u2026]] \fIinstallables\fR\[u2026]
.SH
Examples
.IP "\(bu" 3
Show the \fBstore derivation\fR that results from evaluating the Hello
package:
.LP
.EX
# nix derivation show nixpkgs#hello
{
\(dq/nix/store/s6rn4jz1sin56rf4qj5b5v8jxjm32hlk-hello-2.10.drv\(dq: {
  …
}
}
.EE
.IP "\(bu" 3
Show the full derivation graph (if available) that produced your
NixOS system:
.LP
.EX
# nix derivation show -r /run/current-system
.EE
.IP "\(bu" 3
Print all files fetched using \fCfetchurl\fR by Firefox\(cqs dependency
graph:
.LP
.EX
# nix derivation show -r nixpkgs#firefox \e
| jq -r '.[] | select(.outputs.out.hash and .env.urls) | .env.urls' \e
| uniq | sort
.EE
.IP
Note that \fC.outputs.out.hash\fR selects \fIfixed-output derivations\fR
(derivations that produce output with a specified content hash),
while \fC.env.urls\fR selects derivations with a \fCurls\fR attribute.
.SH
Description
.LP
This command prints on standard output a JSON representation of the
\fBstore derivation\fRs to which \fB\fIinstallables\fR\fR evaluate.
.PP
Store derivations are used internally by Nix. They are store paths with
extension \fC.drv\fR that represent the build-time dependency graph to which
a Nix expression evaluates.
.PP
By default, this command only shows top-level derivations, but with
\fC--recursive\fR, it also shows their dependencies.
.PP
\fCnix derivation show\fR outputs a JSON map of \fBstore path\fRs to derivations in the following format:
.PP
{{#include ../../protocols/json/derivation.md}}
.SH
Options
.IP "\(bu" 3
\fB\fC--recursive\fR\fR / \fC-r\fR
.IP
Include the dependencies of the specified derivations.
.IP "\(bu" 3
\fB\fC--stdin\fR\fR
.IP
Read installables from the standard input. No default installable applied.
.SS
Common evaluation options
.IP "\(bu" 3
\fB\fC--arg\fR\fR \fIname\fR \fIexpr\fR
.IP
Pass the value \fIexpr\fR as the argument \fIname\fR to Nix functions.
.IP "\(bu" 3
\fB\fC--arg-from-file\fR\fR \fIname\fR \fIpath\fR
.IP
Pass the contents of file \fIpath\fR as the argument \fIname\fR to Nix functions.
.IP "\(bu" 3
\fB\fC--arg-from-stdin\fR\fR \fIname\fR
.IP
Pass the contents of stdin as the argument \fIname\fR to Nix functions.
.IP "\(bu" 3
\fB\fC--argstr\fR\fR \fIname\fR \fIstring\fR
.IP
Pass the string \fIstring\fR as the argument \fIname\fR to Nix functions.
.IP "\(bu" 3
\fB\fC--debugger\fR\fR
.IP
Start an interactive environment if evaluation fails.
.IP "\(bu" 3
\fB\fC--eval-store\fR\fR \fIstore-url\fR
.IP
The \fBURL of the Nix store\fR
to use for evaluation, i.e. to store derivations (\fC.drv\fR files) and inputs referenced by them.
.IP "\(bu" 3
\fB\fC--impure\fR\fR
.IP
Allow access to mutable paths and repositories.
.IP "\(bu" 3
\fB\fC--include\fR\fR / \fC-I\fR \fIpath\fR
.IP
Add \fIpath\fR to the Nix search path. The Nix search path is
initialized from the colon-separated \fB\fCNIX_PATH\fR\fR environment
variable, and is used to look up the location of Nix expressions using \fBpaths\fR enclosed in angle
brackets (i.e., \fC<nixpkgs>\fR).
.IP
For instance, passing
.LP
.EX
-I /home/eelco/Dev
-I /etc/nixos
.EE
.IP
will cause Nix to look for paths relative to \fC/home/eelco/Dev\fR and
\fC/etc/nixos\fR, in that order. This is equivalent to setting the
\fCNIX_PATH\fR environment variable to
.LP
.EX
/home/eelco/Dev:/etc/nixos
.EE
.IP
It is also possible to match paths against a prefix. For example,
passing
.LP
.EX
-I nixpkgs=/home/eelco/Dev/nixpkgs-branch
-I /etc/nixos
.EE
.IP
will cause Nix to search for \fC<nixpkgs/path>\fR in
\fC/home/eelco/Dev/nixpkgs-branch/path\fR and \fC/etc/nixos/nixpkgs/path\fR.
.IP
If a path in the Nix search path starts with \fChttp://\fR or \fChttps://\fR,
it is interpreted as the URL of a tarball that will be downloaded and
unpacked to a temporary location. The tarball must consist of a single
top-level directory. For example, passing
.LP
.EX
-I nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz
.EE
.IP
tells Nix to download and use the current contents of the \fCmaster\fR
branch in the \fCnixpkgs\fR repository.
.IP
The URLs of the tarballs from the official \fCnixos.org\fR channels
(see \fBthe manual page for \fCnix-channel\fR\fR) can be
abbreviated as \fCchannel:<channel-name>\fR. For instance, the
following two flags are equivalent:
.LP
.EX
-I nixpkgs=channel:nixos-21.05
-I nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz
.EE
.IP
You can also fetch source trees using \fBflake URLs\fR and add them to the
search path. For instance,
.LP
.EX
-I nixpkgs=flake:nixpkgs
.EE
.IP
specifies that the prefix \fCnixpkgs\fR shall refer to the source tree
downloaded from the \fCnixpkgs\fR entry in the flake registry. Similarly,
.LP
.EX
-I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05
.EE
.IP
makes \fC<nixpkgs>\fR refer to a particular branch of the
\fCNixOS/nixpkgs\fR repository on GitHub.
.IP "\(bu" 3
\fB\fC--override-flake\fR\fR \fIoriginal-ref\fR \fIresolved-ref\fR
.IP
Override the flake registries, redirecting \fIoriginal-ref\fR to \fIresolved-ref\fR.
.SS
Common flake-related options
.IP "\(bu" 3
\fB\fC--commit-lock-file\fR\fR
.IP
Commit changes to the flake\(cqs lock file.
.IP "\(bu" 3
\fB\fC--inputs-from\fR\fR \fIflake-url\fR
.IP
Use the inputs of the specified flake as registry entries.
.IP "\(bu" 3
\fB\fC--no-registries\fR\fR
.IP
Don\(cqt allow lookups in the flake registries.
.RS
.IP
\fBDEPRECATED\fR
.IP
Use \fB\fC--no-use-registries\fR\fR instead.
.RE
.IP "\(bu" 3
\fB\fC--no-update-lock-file\fR\fR
.IP
Do not allow any updates to the flake\(cqs lock file.
.IP "\(bu" 3
\fB\fC--no-write-lock-file\fR\fR
.IP
Do not write the flake\(cqs newly generated lock file.
.IP "\(bu" 3
\fB\fC--output-lock-file\fR\fR \fIflake-lock-path\fR
.IP
Write the given lock file instead of \fCflake.lock\fR within the top-level flake.
.IP "\(bu" 3
\fB\fC--override-input\fR\fR \fIinput-path\fR \fIflake-url\fR
.IP
Override a specific flake input (e.g. \fCdwarffs/nixpkgs\fR). This implies \fC--no-write-lock-file\fR.
.IP "\(bu" 3
\fB\fC--recreate-lock-file\fR\fR
.IP
Recreate the flake\(cqs lock file from scratch.
.RS
.IP
\fBDEPRECATED\fR
.IP
Use \fB\fCnix flake update\fR\fR instead.
.RE
.IP "\(bu" 3
\fB\fC--reference-lock-file\fR\fR \fIflake-lock-path\fR
.IP
Read the given lock file instead of \fCflake.lock\fR within the top-level flake.
.IP "\(bu" 3
\fB\fC--update-input\fR\fR \fIinput-path\fR
.IP
Update a specific flake input (ignoring its previous entry in the lock file).
.RS
.IP
\fBDEPRECATED\fR
.IP
Use \fB\fCnix flake update\fR\fR instead.
.RE
.SS
Logging-related options
.IP "\(bu" 3
\fB\fC--debug\fR\fR
.IP
Set the logging verbosity level to \(oqdebug\(cq.
.IP "\(bu" 3
\fB\fC--log-format\fR\fR \fIformat\fR
.IP
Set the format of log output; one of \fCraw\fR, \fCinternal-json\fR, \fCbar\fR or \fCbar-with-logs\fR.
.IP "\(bu" 3
\fB\fC--print-build-logs\fR\fR / \fC-L\fR
.IP
Print full build logs on standard error.
.IP "\(bu" 3
\fB\fC--quiet\fR\fR
.IP
Decrease the logging verbosity level.
.IP "\(bu" 3
\fB\fC--verbose\fR\fR / \fC-v\fR
.IP
Increase the logging verbosity level.
.SS
Miscellaneous global options
.IP "\(bu" 3
\fB\fC--help\fR\fR
.IP
Show usage information.
.IP "\(bu" 3
\fB\fC--offline\fR\fR
.IP
Disable substituters and consider all previously downloaded files up-to-date.
.IP "\(bu" 3
\fB\fC--option\fR\fR \fIname\fR \fIvalue\fR
.IP
Set the Nix configuration setting \fIname\fR to \fIvalue\fR (overriding \fCnix.conf\fR).
.IP "\(bu" 3
\fB\fC--refresh\fR\fR
.IP
Consider all previously downloaded files out-of-date.
.IP "\(bu" 3
\fB\fC--repair\fR\fR
.IP
During evaluation, rewrite missing or corrupted files in the Nix store. During building, rebuild missing or corrupted store paths.
.IP "\(bu" 3
\fB\fC--version\fR\fR
.IP
Show version information.
.SS
Options that change the interpretation of \fBinstallables\fR
.IP "\(bu" 3
\fB\fC--expr\fR\fR \fIexpr\fR
.IP
Interpret \fB\fIinstallables\fR\fR as attribute paths relative to the Nix expression \fIexpr\fR.
.IP "\(bu" 3
\fB\fC--file\fR\fR / \fC-f\fR \fIfile\fR
.IP
Interpret \fB\fIinstallables\fR\fR as attribute paths relative to the Nix expression stored in \fIfile\fR. If \fIfile\fR is the character -, then a Nix expression will be read from standard input. Implies \fC--impure\fR.
.RS
.LP
\fBNote\fR
.PP
See \fB\fCman nix.conf\fR\fR for overriding configuration settings with command line flags.
.RE