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+# Name
+
+`nix.conf` - Nix configuration file
+
+# Description
+
+By default Nix reads settings from the following places:
+
+  - The system-wide configuration file `sysconfdir/nix/nix.conf` (i.e.
+    `/etc/nix/nix.conf` on most systems), or `$NIX_CONF_DIR/nix.conf` if
+    `NIX_CONF_DIR` is set. Values loaded in this file are not forwarded
+    to the Nix daemon. The client assumes that the daemon has already
+    loaded them.
+
+  - If `NIX_USER_CONF_FILES` is set, then each path separated by `:`
+    will be loaded in reverse order.
+
+    Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS`
+    and `XDG_CONFIG_HOME`. If these are unset, it will look in
+    `$HOME/.config/nix.conf`.
+
+  - If `NIX_CONFIG` is set, its contents is treated as the contents of
+    a configuration file.
+
+The configuration files consist of `name = value` pairs, one per
+line. Other files can be included with a line like `include path`,
+where *path* is interpreted relative to the current conf file and a
+missing file is an error unless `!include` is used instead. Comments
+start with a `#` character. Here is an example configuration file:
+
+    keep-outputs = true       # Nice for developers
+    keep-derivations = true   # Idem
+
+You can override settings on the command line using the `--option`
+flag, e.g. `--option keep-outputs false`. Every configuration setting
+also has a corresponding command line flag, e.g. `--max-jobs 16`; for
+Boolean settings, there are two flags to enable or disable the setting
+(e.g. `--keep-failed` and `--no-keep-failed`).
+
+A configuration setting usually overrides any previous value. However,
+you can prefix the name of the setting by `extra-` to *append* to the
+previous value. For instance,
+
+    substituters = a b
+    extra-substituters = c d
+
+defines the `substituters` setting to be `a b c d`. This is also
+available as a command line flag (e.g. `--extra-substituters`).
+
+The following settings are currently available:
+