aboutsummaryrefslogtreecommitdiff
path: root/src/libcmd
diff options
context:
space:
mode:
Diffstat (limited to 'src/libcmd')
-rw-r--r--src/libcmd/common-eval-args.cc36
1 files changed, 22 insertions, 14 deletions
diff --git a/src/libcmd/common-eval-args.cc b/src/libcmd/common-eval-args.cc
index 53595cea6..dc0de4b9f 100644
--- a/src/libcmd/common-eval-args.cc
+++ b/src/libcmd/common-eval-args.cc
@@ -36,21 +36,29 @@ MixEvalArgs::MixEvalArgs()
Add *path* to the Nix search path. The Nix search path is
initialized from the colon-separated [`NIX_PATH`](./env-common.md#env-NIX_PATH) environment
variable, and is used to look up the location of Nix expressions using [paths](../language/values.md#type-path) enclosed in angle
- brackets (i.e., `<nixpkgs>`). For instance, if the Nix search path
- consists of the entries
+ brackets (i.e., `<nixpkgs>`).
+
+ For instance, passing
+
+ ```
+ -I /home/eelco/Dev
+ -I /etc/nixos
+ ```
+
+ will cause Nix to look for paths relative to `/home/eelco/Dev` and
+ `/etc/nixos`, in that order. This is equivalent to setting the
+ `NIX_PATH` environment variable to
```
- /home/eelco/Dev
- /etc/nixos
+ /home/eelco/Dev:/etc/nixos
```
- Nix will look for paths relative to `/home/eelco/Dev` and
- `/etc/nixos`, in this order. It is also possible to match paths
- against a prefix. For example, the search path
+ It is also possible to match paths against a prefix. For example,
+ passing
```
- nixpkgs=/home/eelco/Dev/nixpkgs-branch
- /etc/nixos
+ -I nixpkgs=/home/eelco/Dev/nixpkgs-branch
+ -I /etc/nixos
```
will cause Nix to search for `<nixpkgs/path>` in
@@ -59,10 +67,10 @@ MixEvalArgs::MixEvalArgs()
If a path in the Nix search path starts with `http://` or `https://`,
it is interpreted as the URL of a tarball that will be downloaded and
unpacked to a temporary location. The tarball must consist of a single
- top-level directory. For example, setting `NIX_PATH` to
+ top-level directory. For example, passing
```
- nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz
+ -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz
```
tells Nix to download and use the current contents of the `master`
@@ -71,11 +79,11 @@ MixEvalArgs::MixEvalArgs()
The URLs of the tarballs from the official `nixos.org` channels
(see [the manual page for `nix-channel`](nix-channel.md)) can be
abbreviated as `channel:<channel-name>`. For instance, the
- following two values of `NIX_PATH` are equivalent:
+ following two flags are equivalent:
```
- nixpkgs=channel:nixos-21.05
- nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz
+ -I nixpkgs=channel:nixos-21.05
+ -I nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz
```
)",
.category = category,