Reputation: 1927
Use the command flag looked like a solution but it doesn't work
Inside the following shell:
nix shell github:nixos/nixpkgs/nixpkgs-unstable#hello
the path contain a directory with an executable hello
I've tried this:
nix shell github:nixos/nixpkgs/nixpkgs-unstable#hello --command echo $PATH
I can't see the hello executable
My eyes are not the problem.
diff <( echo $PATH ) <( nix shell github:nixos/nixpkgs/nixpkgs-unstable#hello --command echo $PATH)
It see no difference. It means that the printed path doesn't not contains hello.
Why?
Upvotes: 0
Views: 270
Reputation: 296049
The printed path does not contain hello
because if your starting PATH was /nix/var/nix/profiles/default/bin:/run/current-system/sw/bin
, then you just ran:
nix shell 'github:nixos/nixpkgs/nixpkgs-unstable#hello' --command \
echo /nix/var/nix/profiles/default/bin:/run/current-system/sw/bin
That is to say, you passed your original path as an argument to the nix shell
command, instead of passing it a reference to a variable for it to expand later.
The easiest way to accomplish what you're looking for is:
nix shell 'github:nixos/nixpkgs/nixpkgs-unstable#hello' --command \
sh -c 'echo "$PATH"'
The single quotes prevent your shell from expanding $PATH
before a copy of sh
invoked by nix is started.
Of course, if you really don't want to start any kind of child shell, then you can run a non-shell tool to print environment variables:
nix shell 'github:nixos/nixpkgs/nixpkgs-unstable#hello' --command \
env | grep '^PATH='
Upvotes: 2