.\" -*- mode: troff; coding: utf-8 -*-
.TH "nix3-flake-info" "1" ""
.RS
.PP
\fBWarning\fR 
.br
This program is
\fB\fBexperimental\fR\fR
and its interface is subject to change.
.RE
.SH Name
.LP
\f(CRnix flake info\fR - show flake metadata
.SH Synopsis
.LP
\f(CRnix flake info\fR [\fIoption\fR\[u2026]] \fIflake-url\fR
.SH Examples
.IP "\(bu" 3
Show what \f(CRdwarffs\fR resolves to:
.LP
.EX
# nix flake metadata dwarffs
Resolved URL:  github:edolstra/dwarffs
Locked URL:    github:edolstra/dwarffs/f691e2c991e75edb22836f1dbe632c40324215c5
Description:   A filesystem that fetches DWARF debug info from the Internet on demand
Path:          /nix/store/769s05vjydmc2lcf6b02az28wsa9ixh1-source
Revision:      f691e2c991e75edb22836f1dbe632c40324215c5
Last modified: 2021-01-21 15:41:26
Inputs:
├───nix: github:NixOS/nix/6254b1f5d298ff73127d7b0f0da48f142bdc753c
│   ├───lowdown-src: github:kristapsdz/lowdown/1705b4a26fbf065d9574dce47a94e8c7c79e052f
│   └───nixpkgs: github:NixOS/nixpkgs/ad0d20345219790533ebe06571f82ed6b034db31
└───nixpkgs follows input 'nix/nixpkgs'
.EE
.IP "\(bu" 3
Show information about \f(CRdwarffs\fR in JSON format:
.LP
.EX
# nix flake metadata dwarffs --json | jq .
{
\(dqdescription\(dq: \(dqA filesystem that fetches DWARF debug info from the Internet on demand\(dq,
\(dqlastModified\(dq: 1597153508,
\(dqlocked\(dq: {
  \(dqlastModified\(dq: 1597153508,
  \(dqnarHash\(dq: \(dqsha256-VHg3MYVgQ12LeRSU2PSoDeKlSPD8PYYEFxxwkVVDRd0=\(dq,
  \(dqowner\(dq: \(dqedolstra\(dq,
  \(dqrepo\(dq: \(dqdwarffs\(dq,
  \(dqrev\(dq: \(dqd181d714fd36eb06f4992a1997cd5601e26db8f5\(dq,
  \(dqtype\(dq: \(dqgithub\(dq
},
\(dqlocks\(dq: { ... },
\(dqoriginal\(dq: {
  \(dqid\(dq: \(dqdwarffs\(dq,
  \(dqtype\(dq: \(dqindirect\(dq
},
\(dqoriginalUrl\(dq: \(dqflake:dwarffs\(dq,
\(dqpath\(dq: \(dq/nix/store/hang3792qwdmm2n0d9nsrs5n6bsws6kv-source\(dq,
\(dqresolved\(dq: {
  \(dqowner\(dq: \(dqedolstra\(dq,
  \(dqrepo\(dq: \(dqdwarffs\(dq,
  \(dqtype\(dq: \(dqgithub\(dq
},
\(dqresolvedUrl\(dq: \(dqgithub:edolstra/dwarffs\(dq,
\(dqrevision\(dq: \(dqd181d714fd36eb06f4992a1997cd5601e26db8f5\(dq,
\(dqurl\(dq: \(dqgithub:edolstra/dwarffs/d181d714fd36eb06f4992a1997cd5601e26db8f5\(dq
}
.EE
.SH Description
.LP
This command shows information about the flake specified by the flake
reference \fIflake-url\fR. It resolves the flake reference using the
\fBflake registry\fR, fetches it, and prints some meta
data. This includes:
.IP "\(bu" 3
\f(CRResolved URL\fR: If \fIflake-url\fR is a flake identifier, then this is
the flake reference that specifies its actual location, looked up in
the flake registry.
.IP "\(bu" 3
\f(CRLocked URL\fR: A flake reference that contains a commit or content
hash and thus uniquely identifies a specific flake version.
.IP "\(bu" 3
\f(CRDescription\fR: A one-line description of the flake, taken from the
\f(CRdescription\fR field in \f(CRflake.nix\fR.
.IP "\(bu" 3
\f(CRPath\fR: The store path containing the source code of the flake.
.IP "\(bu" 3
\f(CRRevision\fR: The Git or Mercurial commit hash of the locked flake.
.IP "\(bu" 3
\f(CRRevisions\fR: The number of ancestors of the Git or Mercurial commit
of the locked flake. Note that this is not available for \f(CRgithub\fR
flakes.
.IP "\(bu" 3
\f(CRLast modified\fR: For Git or Mercurial flakes, this is the commit
time of the commit of the locked flake; for tarball flakes, it\(cqs the
most recent timestamp of any file inside the tarball.
.IP "\(bu" 3
\f(CRInputs\fR: The flake inputs with their corresponding lock file
entries.
.LP
With \f(CR--json\fR, the output is a JSON object with the following fields:
.IP "\(bu" 3
\f(CRoriginal\fR and \f(CRoriginalUrl\fR: The flake reference specified by the
user (\fIflake-url\fR) in attribute set and URL representation.
.IP "\(bu" 3
\f(CRresolved\fR and \f(CRresolvedUrl\fR: The resolved flake reference (see
above) in attribute set and URL representation.
.IP "\(bu" 3
\f(CRlocked\fR and \f(CRlockedUrl\fR: The locked flake reference (see above) in
attribute set and URL representation.
.IP "\(bu" 3
\f(CRdescription\fR: See \f(CRDescription\fR above.
.IP "\(bu" 3
\f(CRpath\fR: See \f(CRPath\fR above.
.IP "\(bu" 3
\f(CRrevision\fR: See \f(CRRevision\fR above.
.IP "\(bu" 3
\f(CRrevCount\fR: See \f(CRRevisions\fR above.
.IP "\(bu" 3
\f(CRlastModified\fR: See \f(CRLast modified\fR above.
.IP "\(bu" 3
\f(CRlocks\fR: The contents of \f(CRflake.lock\fR.
.SH Options
.IP "\(bu" 3
\fB\f(CR--json\fR\fR
.IP
Produce output in JSON format, suitable for consumption by another program.
.SS
Common evaluation options
.IP "\(bu" 3
\fB\f(CR--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\f(CR--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\f(CR--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\f(CR--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\f(CR--debugger\fR\fR
.IP
Start an interactive environment if evaluation fails.
.IP "\(bu" 3
\fB\f(CR--eval-store\fR\fR \fIstore-url\fR
.IP
The \fBURL of the Nix store\fR
to use for evaluation, i.e. to store derivations (\f(CR.drv\fR files) and inputs referenced by them.
.IP "\(bu" 3
\fB\f(CR--impure\fR\fR
.IP
Allow access to mutable paths and repositories.
.IP "\(bu" 3
\fB\f(CR--include\fR\fR / \f(CR-I\fR \fIpath\fR
.IP
Add \fIpath\fR to search path entries used to resolve \fBlookup paths\fR
.IP
This option may be given multiple times.
.IP
Paths added through \f(CR-I\fR take precedence over the \fB\f(CRnix-path\fR configuration setting\fR and the \fB\f(CRNIX_PATH\fR environment variable\fR.
.IP "\(bu" 3
\fB\f(CR--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\f(CR--commit-lock-file\fR\fR
.IP
Commit changes to the flake\(cqs lock file.
.IP "\(bu" 3
\fB\f(CR--inputs-from\fR\fR \fIflake-url\fR
.IP
Use the inputs of the specified flake as registry entries.
.IP "\(bu" 3
\fB\f(CR--no-registries\fR\fR
.IP
Don\(cqt allow lookups in the flake registries.
.RS
.IP
\fBDEPRECATED\fR
.IP
Use \fB\f(CR--no-use-registries\fR\fR instead.
.RE
.IP "\(bu" 3
\fB\f(CR--no-update-lock-file\fR\fR
.IP
Do not allow any updates to the flake\(cqs lock file.
.IP "\(bu" 3
\fB\f(CR--no-write-lock-file\fR\fR
.IP
Do not write the flake\(cqs newly generated lock file.
.IP "\(bu" 3
\fB\f(CR--output-lock-file\fR\fR \fIflake-lock-path\fR
.IP
Write the given lock file instead of \f(CRflake.lock\fR within the top-level flake.
.IP "\(bu" 3
\fB\f(CR--override-input\fR\fR \fIinput-path\fR \fIflake-url\fR
.IP
Override a specific flake input (e.g. \f(CRdwarffs/nixpkgs\fR). This implies \f(CR--no-write-lock-file\fR.
.IP "\(bu" 3
\fB\f(CR--recreate-lock-file\fR\fR
.IP
Recreate the flake\(cqs lock file from scratch.
.RS
.IP
\fBDEPRECATED\fR
.IP
Use \fB\f(CRnix flake update\fR\fR instead.
.RE
.IP "\(bu" 3
\fB\f(CR--reference-lock-file\fR\fR \fIflake-lock-path\fR
.IP
Read the given lock file instead of \f(CRflake.lock\fR within the top-level flake.
.IP "\(bu" 3
\fB\f(CR--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\f(CRnix flake update\fR\fR instead.
.RE
.SS
Logging-related options
.IP "\(bu" 3
\fB\f(CR--debug\fR\fR
.IP
Set the logging verbosity level to \(oqdebug\(cq.
.IP "\(bu" 3
\fB\f(CR--log-format\fR\fR \fIformat\fR
.IP
Set the format of log output; one of \f(CRraw\fR, \f(CRinternal-json\fR, \f(CRbar\fR or \f(CRbar-with-logs\fR.
.IP "\(bu" 3
\fB\f(CR--print-build-logs\fR\fR / \f(CR-L\fR
.IP
Print full build logs on standard error.
.IP "\(bu" 3
\fB\f(CR--quiet\fR\fR
.IP
Decrease the logging verbosity level.
.IP "\(bu" 3
\fB\f(CR--verbose\fR\fR / \f(CR-v\fR
.IP
Increase the logging verbosity level.
.SS
Miscellaneous global options
.IP "\(bu" 3
\fB\f(CR--help\fR\fR
.IP
Show usage information.
.IP "\(bu" 3
\fB\f(CR--offline\fR\fR
.IP
Disable substituters and consider all previously downloaded files up-to-date.
.IP "\(bu" 3
\fB\f(CR--option\fR\fR \fIname\fR \fIvalue\fR
.IP
Set the Nix configuration setting \fIname\fR to \fIvalue\fR (overriding \f(CRnix.conf\fR).
.IP "\(bu" 3
\fB\f(CR--refresh\fR\fR
.IP
Consider all previously downloaded files out-of-date.
.IP "\(bu" 3
\fB\f(CR--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\f(CR--version\fR\fR
.IP
Show version information.
.RS
.LP
\fBNote\fR
.PP
See \fB\f(CRman nix.conf\fR\fR for overriding configuration settings with command line flags.
.RE