-- `run cmd argv > R (M t t) t` — argv-list process spawn. No shell, no
-- glob, no interpolation. Result Err only on spawn failure; a non-zero
-- exit code surfaces as Ok({"code":"<n>",...}).
stdout-of>t;m=run!! "echo" ["hi"];??mget m "stdout" ""
code-of-false>t;m=run!! "false" [];??mget m "code" ""
code-of-true>t;m=run!! "true" [];??mget m "code" ""
-- argv entries are passed verbatim — printf proves each list element
-- is one distinct argv slot, with no shell-style join.
argv-roundtrip>t;m=run!! "printf" ["%s|%s|%s" "a" "b" "c"];??mget m "stdout" ""
-- $ sigil is the run shortcut (0.12.0 rebind from HTTP get).
sigil-echo>t;m=$!!"echo" ["hi"];??mget m "stdout" ""
-- engine-skip: jit
-- run: stdout-of
-- out: hi
-- run: code-of-false
-- out: 1
-- run: code-of-true
-- out: 0
-- run: argv-roundtrip
-- out: a|b|c
-- run: sigil-echo
-- out: hi