Add directory to $PATH

[woutervh]

using just 1.38.0:

Usecase: I want to add the bin-directory of my python virtualenv to $PATH for all recipes:

venv_bin_dir := justfile_directory() + "/.venv/bin"   # resolves to correct folder

export PATH := "{{venv_bin_dir}}:${PATH}"  # error


demo:
    @ echo "abs venv_bin: {{venv_bin_dir}}"

but this fails with:

error: Recipe `demo` could not be run because just could not find the shell: No such file or directory (os error 2)

This also fails:

venv_bin_dir := justfile_directory() + "/.venv/bin"
OLD_PATH := env("PATH")
export PATH := "{{venv_bin_dir}}:{{OLD_PATH}}"

am I using the wrong syntax?
Is this a bug? Or not implemented?

[laniakea64]

1. Interpolations in strings are not currently implemented, see Allow interpolation inside of backticks and strings #11

2. Shell-expanded strings are prefixed with x.

So try this? -

venv_bin_dir := justfile_directory() / ".venv/bin"
export PATH := venv_bin_dir + x':${PATH}'

[casey]

@laniakea64's suggestion should work. This does make me think that perhaps we should provide a cross-paltform function to add directories to PATH, since windows uses ;.

[woutervh]

this syntax indeed works

venv_bin_dir := justfile_directory() / ".venv/bin"
export PATH := venv_bin_dir + x':${PATH}'

but again the same error when tying to make it crossplatform with:

export PATH := if os_family() == "windows" { venv_bin_dir + ";${PATH}" } else { venv_bin_dir + ":${PATH}" }

[laniakea64]

That line is missing the x prefix on the strings intended to be shell-expanded:

export PATH := if os_family() == "windows" { venv_bin_dir + x";${PATH}" } else { venv_bin_dir + x":${PATH}" }

[woutervh]

As Homer would say "Dooh!"
Many thanks.

[woutervh]

see also #2597