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| -rw-r--r-- | doc/guix.texi | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index d0dc523a01..cfa5aac326 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -95,7 +95,7 @@ always produces the same result when passed a given set of inputs. It cannot alter the system's environment in any way; for instance, it cannot create, modify, or delete files outside of its build and installation directories. This is achieved by running -build processes in isolated environments (or @dfn{chroots}), where only their +build processes in isolated environments (or @dfn{containers}), where only their explicit inputs are visible. @cindex store @@ -224,6 +224,7 @@ The @code{guix-daemon} program may then be run as @code{root} with: # guix-daemon --build-users-group=guix-builder @end example +@cindex chroot @noindent This way, the daemon starts build processes in a chroot, under one of the @code{guix-builder} users. On GNU/Linux, by default, the chroot @@ -271,6 +272,10 @@ is normally run as @code{root} like this: @noindent For details on how to set it up, @ref{Setting Up the Daemon}. +@cindex chroot +@cindex container, build environment +@cindex build environment +@cindex reproducible builds By default, @command{guix-daemon} launches build processes under different UIDs, taken from the build group specified with @code{--build-users-group}. In addition, each build process is run in a @@ -278,7 +283,10 @@ chroot environment that only contains the subset of the store that the build process depends on, as specified by its derivation (@pxref{Programming Interface, derivation}), plus a set of specific system directories. By default, the latter contains @file{/dev} and -@file{/dev/pts}. +@file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a +@dfn{container}: in addition to having its own file system tree, it has +a separate mount name space, its own PID name space, network name space, +etc. This helps achieve reproducible builds (@pxref{Features}). The following command-line options are supported: @@ -447,13 +455,18 @@ profiles, and remove those that are provably no longer referenced generations of their profile so that the packages they refer to can be collected. +@cindex reproducibility +@cindex reproducible builds Finally, Guix takes a @dfn{purely functional} approach to package management, as described in the introduction (@pxref{Introduction}). Each @file{/nix/store} package directory name contains a hash of all the inputs that were used to build that package---compiler, libraries, build scripts, etc. This direct correspondence allows users to make sure a given package installation matches the current state of their -distribution, and helps maximize @dfn{reproducibility}. +distribution. It also helps maximize @dfn{build reproducibility}: +thanks to the isolated build environments that are used, a given build +is likely to yield bit-identical files when performed on different +machines (@pxref{Invoking guix-daemon, container}). @cindex substitute This foundation allows Guix to support @dfn{transparent binary/source |