Hojun-Cho
cd408195fa
sepscratch_test.ww pins the #59 build_one_sep scratch ownership on both driver stages: build -o keeps <stem>.sepwork, `run` leaves no /tmp/ww_run_<pid> root, and a foreign pre-existing .sepwork is refused with exit exactly 1, sentinel intact. The C fork/execl pid capture becomes `sh -c 'echo $$ ...; exec <drv> run ...'` -- exec keeps the shell's pid and passes the full driver path as argv[0].