devbox run -- cmd ARG: a newline in ARG becomes a literal \n, and a quoted $ is expanded #2998

Devbox 0.18.4, Linux (Ubuntu 24.04).

devbox run -- cmd ARG... does not pass the arguments through unchanged. It looks like the arguments are joined into one shell string and parsed again.

1. A newline in an argument becomes a literal \n.

devbox run -q -- node -e 'console.log(JSON.stringify(process.argv.slice(1)))' -- $'a\nb' "c d"

Expected: ["a\nb","c d"] (a real newline in the first argument)
Actual: ["a\\nb","c d"] (a backslash and an n)

Spaces survive, newlines do not. So a multi-line node -e or bash -c script does not parse under devbox run.

2. A $ in an argument is expanded, also when the caller quoted it.

devbox run -q -- printf '%s\n' 'a$HOME'
# expected: a$HOME
# actual:   a/home/<user>

devbox run -q -- bash -c 'X=inner; echo "[$X]"'
# expected: [inner]
# actual:   []

Workaround: write the script to a file and pass its path.

Expected behaviour: the arguments after -- reach the command exactly as the caller's shell gave them (as with exec "$@").