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Diffstat (limited to 'doc/guix.texi')
| -rw-r--r-- | doc/guix.texi | 59 |
1 files changed, 57 insertions, 2 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index ed88778016..bc1d5d863a 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -198,6 +198,7 @@ Package Management * Invoking guix gc:: Running the garbage collector. * Invoking guix pull:: Fetching the latest Guix and distribution. * Channels:: Customizing the package collection. +* Invoking guix time-machine:: Running an older revision of Guix. * Inferiors:: Interacting with another revision of Guix. * Invoking guix describe:: Display information about your Guix revision. * Invoking guix archive:: Exporting and importing store files. @@ -2550,6 +2551,7 @@ guix install emacs-guix * Invoking guix gc:: Running the garbage collector. * Invoking guix pull:: Fetching the latest Guix and distribution. * Channels:: Customizing the package collection. +* Invoking guix time-machine:: Running an older revision of Guix. * Inferiors:: Interacting with another revision of Guix. * Invoking guix describe:: Display information about your Guix revision. * Invoking guix archive:: Exporting and importing store files. @@ -4152,7 +4154,10 @@ say, on another machine, by providing a channel specification in @end lisp The @command{guix describe --format=channels} command can even generate this -list of channels directly (@pxref{Invoking guix describe}). +list of channels directly (@pxref{Invoking guix describe}). The resulting +file can be used with the -C options of @command{guix pull} +(@pxref{Invoking guix pull}) or @command{guix time-machine} +(@pxref{Invoking guix time-machine}). At this point the two machines run the @emph{exact same Guix}, with access to the @emph{exact same packages}. The output of @command{guix build gimp} on @@ -4166,6 +4171,57 @@ artifacts with very fine grain, and to reproduce software environments at will---some sort of ``meta reproducibility'' capabilities, if you will. @xref{Inferiors}, for another way to take advantage of these super powers. +@node Invoking guix time-machine +@section Invoking @command{guix time-machine} + +@cindex @command{guix time-machine} +@cindex pinning, channels +@cindex replicating Guix +@cindex reproducibility, of Guix + +The @command{guix time-machine} command provides access to other +revisions of Guix, for example to install older versions of packages, +or to reproduce a computation in an identical environment. The revision +of Guix to be used is defined by a commit or by a channel +description file created by @command{guix describe} +(@pxref{Invoking guix describe}). + +The general syntax is: + +@example +guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{} +@end example + +where @var{command} and @var{arg}@dots{} are passed unmodified to the +@command{guix} command if the specified revision. The @var{options} that define +this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}): + +@table @code +@item --url=@var{url} +@itemx --commit=@var{commit} +@itemx --branch=@var{branch} +Use the @code{guix} channel from the specified @var{url}, at the +given @var{commit} (a valid Git commit ID represented as a hexadecimal +string), or @var{branch}. + +@item --channels=@var{file} +@itemx -C @var{file} +Read the list of channels from @var{file}. @var{file} must contain +Scheme code that evaluates to a list of channel objects. +@xref{Channels} for more information. +@end table + +As for @command{guix pull}, the absence of any options means that the +the latest commit on the master branch will be used. The command + +@example +guix time-machine -- build hello +@end example + +will thus build the package @code{hello} as defined in the master branch, +which is in general a newer revison of Guix than you have installed. +Time travel works in both directions! + @node Inferiors @section Inferiors @@ -10589,7 +10645,6 @@ ClientPID: 19419 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{} @end example - @node System Configuration @chapter System Configuration |