'\" t
.\"     Title: nix-copy-closure
.\"    Author: Eelco Dolstra
.\" Generator: DocBook XSL Stylesheets v1.79.2 <http://docbook.sf.net/>
.\"      Date: 12/12/2020
.\"    Manual: Command Reference
.\"    Source: Nix 2.3.7
.\"  Language: English
.\"
.TH "NIX\-COPY\-CLOSURE" "1" "12/12/2020" "Nix 2\&.3\&.7" "Command Reference"
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.SH "NAME"
nix-copy-closure \- copy a closure to or from a remote machine via SSH
.SH "SYNOPSIS"
.HP \w'\fBnix\-copy\-closure\fR\ 'u
\fBnix\-copy\-closure\fR [\fB\-\-to\fR | \fB\-\-from\fR] [\fB\-\-gzip\fR] [\fB\-\-include\-outputs\fR] [\fB\-\-use\-substitutes\fR | \fB\-s\fR] [\fB\-v\fR] \fIuser@\fR\fImachine\fR \fIpaths\fR
.SH "DESCRIPTION"
.PP
\fBnix\-copy\-closure\fR
gives you an easy and efficient way to exchange software between machines\&. Given one or more Nix store
\fIpaths\fR
on the local machine,
\fBnix\-copy\-closure\fR
computes the closure of those paths (i\&.e\&. all their dependencies in the Nix store), and copies all paths in the closure to the remote machine via the
\fBssh\fR
(Secure Shell) command\&. With the
\fB\-\-from\fR, the direction is reversed: the closure of
\fIpaths\fR
on a remote machine is copied to the Nix store on the local machine\&.
.PP
This command is efficient because it only sends the store paths that are missing on the target machine\&.
.PP
Since
\fBnix\-copy\-closure\fR
calls
\fBssh\fR, you may be asked to type in the appropriate password or passphrase\&. In fact, you may be asked
\fItwice\fR
because
\fBnix\-copy\-closure\fR
currently connects twice to the remote machine, first to get the set of paths missing on the target machine, and second to send the dump of those paths\&. If this bothers you, use
\fBssh\-agent\fR\&.
.SS "Options"
.PP
\fB\-\-to\fR
.RS 4
Copy the closure of
\fIpaths\fR
from the local Nix store to the Nix store on
\fImachine\fR\&. This is the default\&.
.RE
.PP
\fB\-\-from\fR
.RS 4
Copy the closure of
\fIpaths\fR
from the Nix store on
\fImachine\fR
to the local Nix store\&.
.RE
.PP
\fB\-\-gzip\fR
.RS 4
Enable compression of the SSH connection\&.
.RE
.PP
\fB\-\-include\-outputs\fR
.RS 4
Also copy the outputs of store derivations included in the closure\&.
.RE
.PP
\fB\-\-use\-substitutes\fR / \fB\-s\fR
.RS 4
Attempt to download missing paths on the target machine using Nix\(cqs substitute mechanism\&. Any paths that cannot be substituted on the target are still copied normally from the source\&. This is useful, for instance, if the connection between the source and target machine is slow, but the connection between the target machine and
nixos\&.org
(the default binary cache server) is fast\&.
.RE
.PP
\fB\-v\fR
.RS 4
Show verbose output\&.
.RE
.SS "Environment variables"
.PP
\fBNIX_SSHOPTS\fR
.RS 4
Additional options to be passed to
\fBssh\fR
on the command line\&.
.RE
.SS "Examples"
.PP
Copy Firefox with all its dependencies to a remote machine:
.sp
.if n \{\
.RS 4
.\}
.nf
$ nix\-copy\-closure \-\-to alice@itchy\&.labs $(type \-tP firefox)
.fi
.if n \{\
.RE
.\}
.PP
Copy Subversion from a remote machine and then install it into a user environment:
.sp
.if n \{\
.RS 4
.\}
.nf
$ nix\-copy\-closure \-\-from alice@itchy\&.labs \e
    /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy\-subversion\-1\&.4\&.4
$ nix\-env \-i /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy\-subversion\-1\&.4\&.4
.fi
.if n \{\
.RE
.\}
.sp
.SH "AUTHOR"
.PP
\fBEelco Dolstra\fR
.RS 4
Author
.RE
.SH "COPYRIGHT"
.br
Copyright \(co 2004-2018 Eelco Dolstra
.br