diff --git a/doc/manual/conf-file.xml b/doc/manual/conf-file.xml index 79faa05fd..acf0eb4f5 100644 --- a/doc/manual/conf-file.xml +++ b/doc/manual/conf-file.xml @@ -118,6 +118,123 @@ env-keep-derivations = false + build-max-silent-time + + + + This option defines the maximum number of seconds that a + builder can go without producing any data on standard output or + standard error. This is useful (for instance in a automated + build system) to catch builds that are stuck in an infinite + loop, or to catch remote builds that are hanging due to network + problems. It can be overriden using the command + line switch. + + The value 0 means that there is no + timeout. This is also the default. + + + + + + + build-users-group + + This options specifies the Unix group containing + the Nix build user accounts. In multi-user Nix installations, + builds should not be performed by the Nix account since that would + allow users to arbitrarily modify the Nix store and database by + supplying specially crafted builders; and they cannot be performed + by the calling user since that would allow him/her to influence + the build result. + + Therefore, if this option is non-empty and specifies a valid + group, builds will be performed under the user accounts that are a + member of the group specified here (as listed in + /etc/group). Those user accounts should not + be used for any other purpose! + + Nix will never run two builds under the same user account at + the same time. This is to prevent an obvious security hole: a + malicious user writing a Nix expression that modifies the build + result of a legitimate Nix expression being built by another user. + Therefore it is good to have as many Nix build user accounts as + you can spare. (Remember: uids are cheap.) + + The build users should have permission to create files in + the Nix store, but not delete them. Therefore, + /nix/store should be owned by the Nix + account, its group should be the group specified here, and its + mode should be 1775. + + If the build users group is empty, builds will be performed + under the uid of the Nix process (that is, the uid of the caller + if NIX_REMOTE is empty, the uid under which the Nix + daemon runs if NIX_REMOTE is + daemon, or the uid that owns the setuid + nix-worker program if NIX_REMOTE + is slave). Obviously, this should not be used + in multi-user settings with untrusted users. + + + + + + + build-use-chroot + + If set to true, builds will be + performed in a chroot environment, i.e., the + build will be isolated from the normal file system hierarchy and + will only see the Nix store, the temporary build directory, and + the directories configured with the build-chroot-dirs + option (such as /proc and + /dev). This is useful to prevent undeclared + dependencies on files in directories such as + /usr/bin. + + The use of a chroot requires that Nix is run as root (but + you can still use the “build users” feature to + perform builds under different users than root). Currently, + chroot builds only work on Linux because Nix uses “bind mounts” to + make the Nix store and other directories available inside the + chroot. + + + + + + + build-chroot-dirs + + When builds are performed in a chroot environment, + Nix will mount (using mount --bind on Linux) + some directories from the normal file system hierarchy inside the + chroot. These are the Nix store, the temporary build directory + (usually + /tmp/nix-pid-number) + and the directories listed here. The default is dev + /proc. Files in /dev (such as + /dev/null) are needed by many builds, and + some files in /proc may also be needed + occasionally. + + The value used on NixOS is + + +build-use-chroot = /dev /proc /bin + + to make the /bin/sh symlink available (which + is still needed by many builders). + + + + + + system This option specifies the canonical Nix system diff --git a/doc/manual/opt-common-syn.xml b/doc/manual/opt-common-syn.xml index 9aaabb8e9..eadc45e3a 100644 --- a/doc/manual/opt-common-syn.xml +++ b/doc/manual/opt-common-syn.xml @@ -13,6 +13,10 @@ number + + + number + diff --git a/doc/manual/opt-common.xml b/doc/manual/opt-common.xml index 1d09fef95..7dfb7b8f8 100644 --- a/doc/manual/opt-common.xml +++ b/doc/manual/opt-common.xml @@ -103,6 +103,17 @@ + + + Sets the maximum number of seconds that a builder + can go without producing any data on standard output or standard + error. The default is specified by the build-max-silent-time + configuration setting. 0 means no + time-out. + + + diff --git a/nix.conf.example b/nix.conf.example index 99a94bfb9..a97554b18 100644 --- a/nix.conf.example +++ b/nix.conf.example @@ -80,7 +80,7 @@ ### Option `build-max-silent-time' # -# This option defines the maximum number of seconds that builder can +# This option defines the maximum number of seconds that a builder can # go without producing any data on standard output or standard error. # This is useful (for instance in a automated build system) to catch # builds that are stuck in an infinite loop, or to catch remote builds