refactor: use pkgs.writeShellApplication

[nekowinston]

Following #1, I had a look through other todo notes, and this would be my approach.

Tried it on my dots again. Seems that only the formatting changed. (cfg.env changed, see my comments)

writeShellApplication already runs shellcheck for us: https://github.com/NixOS/nixpkgs/blob/52544c4a0a84552db4013a8858ade52eaf7ff0ca/pkgs/build-support/trivial-builders/default.nix#L243-L357

[nekowinston]

The current code produces

export FOO="${FOO:-bar}"

while runtimeEnv produces

FOO='bar'
export FOO

[willruggiano]

So this one is actually on purpose. The reason is that writeShellApplication prepends PATH arguments (export PATH="${lib.makeBinPath runtimeInputs}:$PATH") which means that paths can't be overridden (e.g. via direnv/devShell) if you include in them in paths :(

I had planned on submitting an upstream PR to allow appending rather than prepending to PATH, but guess I just forgot :/

[nekowinston]

Interesting, I didn't think of this use case before, but that makes a lot of sense.

Would going back to the previous way of setting $PATH work? e092693

[willruggiano]

Interesting, I didn't think of this use case before, but that makes a lot of sense.

Would going back to the previous way of setting $PATH work? e092693

No, doing so is the equivalent of:

export PATH="${makeBinPath ...}:$PATH" # added by writeShellApplication
export PATH="$PATH:${makeBinPath ...}" # added by us

but when the second export hits, the damage has already been done by writeShellApplication.

[nekowinston]

The first line

export PATH="${makeBinPath ...}:$PATH" # added by writeShellApplication

doesn't get added for me when runtimeInputs == [], see https://github.com/NixOS/nixpkgs/blob/52544c4a0a84552db4013a8858ade52eaf7ff0ca/pkgs/build-support/trivial-builders/default.nix#L330-L333

When I'm building my neovim.drv with e092693, I get:

#!/nix/store/0wzb184kckhmggq1nlvy5xk6rykp0jl1-bash-5.2-p21/bin/bash
set -o errexit
set -o nounset
set -o pipefail
NVIM_RPLUGIN_MANIFEST='/nix/store/6xyawv9vc956jxbmbb5km15r07z8bxjj-rplugin.vim/rplugin.vim'
export NVIM_RPLUGIN_MANIFEST

export PATH="$PATH:/nix/store/dycm8fa8rhxjyfra67s8mnqg4vmig3h3-fd-9.0.0/bin:..."
/nix/store/wfwz9ig0ipl21v1ngxhgndfgsix5h392-neovim-unwrapped-0.9.5/bin/nvim -u /nix/store/m9ji2sl0h44w3831xxpzkpzw6a7d4hk6-init.lua "$@"

And starting PATH=FOO ./result/bin/nvim +'echo $PATH' prepends $PATH for me: FOO:/nix/store/dycm8fa8rhxjyfra67s8mnqg4vmig3h3-fd-9.0.0/bin:....

...sorry if this is coming across as trying to force this PR, just trying to figure out if something changed recently, that leads to different behavior for my build.

[willruggiano]

The first line

export PATH="${makeBinPath ...}:$PATH" # added by writeShellApplication

doesn't get added for me when runtimeInputs == [], see https://github.com/NixOS/nixpkgs/blob/52544c4a0a84552db4013a8858ade52eaf7ff0ca/pkgs/build-support/trivial-builders/default.nix#L330-L333

When I'm building my neovim.drv with e092693, I get:

#!/nix/store/0wzb184kckhmggq1nlvy5xk6rykp0jl1-bash-5.2-p21/bin/bash

set -o errexit

set -o nounset

set -o pipefail

NVIM_RPLUGIN_MANIFEST='/nix/store/6xyawv9vc956jxbmbb5km15r07z8bxjj-rplugin.vim/rplugin.vim'

export NVIM_RPLUGIN_MANIFEST



export PATH="$PATH:/nix/store/dycm8fa8rhxjyfra67s8mnqg4vmig3h3-fd-9.0.0/bin:..."

/nix/store/wfwz9ig0ipl21v1ngxhgndfgsix5h392-neovim-unwrapped-0.9.5/bin/nvim -u /nix/store/m9ji2sl0h44w3831xxpzkpzw6a7d4hk6-init.lua "$@"

And starting PATH=FOO ./result/bin/nvim +'echo $PATH' prepends $PATH for me: FOO:/nix/store/dycm8fa8rhxjyfra67s8mnqg4vmig3h3-fd-9.0.0/bin:....

...sorry if this is coming across as trying to force this PR, just trying to figure out if something changed recently, that leads to different behavior for my build.

Cool I will try it out when I get home!