tools/run.py --parallel runs the full project list once per project

[aspizu]

Repro

tmp=$(mktemp -d /tmp/goboscript-run-parallel-XXXXXX)
for name in one two; do
  mkdir "$tmp/$name"
  printf 'costumes "blank.svg";\n\n' > "$tmp/$name/stage.gs"
  printf '<svg xmlns="http://www.w3.org/2000/svg" width="1" height="1"></svg>\n' > "$tmp/$name/blank.svg"
  cargo run --quiet -- build "$tmp/$name"
done

tmpbin=$(mktemp -d /tmp/goboscript-fake-parallel-XXXXXX)
log="$tmp/parallel.log"
printf '#!/bin/sh\nprintf "%%s\\n" "$*" >> %s\nexit 0\n' "$log" > "$tmpbin/parallel"
chmod +x "$tmpbin/parallel"
PATH="$tmpbin:$PATH" uv run tools/run.py --parallel "$tmp/one" "$tmp/two"
cat "$log"

Observed:

target/debug/goboscript build {} ::: /tmp/.../one /tmp/.../two
target/debug/goboscript build {} ::: /tmp/.../one /tmp/.../two

tools/run.py iterates for project in args.projects, but in parallel mode each iteration invokes GNU parallel with the entire args.projects list. With N projects, it runs N full batches, so every project is built N times.

Expected

Parallel mode should invoke GNU parallel once for the full project list.

[linear]

GS-273