process.stdin never delivers piped input and process.argv does not contain script arguments #49

Test I ran

printf 'l1\nl2\n' | node stdin.ts
printf 'l1\nl2\n' | slice run stdin.ts

node argv.ts a b
slice run argv.ts a b
slice run argv.ts -- a b

stdin.ts

let data = "";
process.stdin.setEncoding("utf8");
process.stdin.on("data", (c) => { data += c; });
process.stdin.on("end", () => { console.log("stdin bytes=" + data.length + " content=" + JSON.stringify(data)); });
setTimeout(() => console.log("after 300ms: bytes so far=" + data.length), 300);

argv.ts

console.log(JSON.stringify({ argvLength: process.argv.length, tail: process.argv.slice(2) }));

Result

stdin.ts   node : stdin bytes=6 content="l1\nl2\n"
           slice: stdin bytes=0 content=""

argv.ts    node            : {"argvLength":4,"tail":["a","b"]}
           slice run … a b : {"argvLength":1,"tail":[]}
           slice run … -- a b : {"argvLength":1,"tail":[]}

node:readline over process.stdin (for await (const line of rl)) likewise yields no lines, while the same interface over Readable.from([...]) works.

What is wrong

• Data piped to the process is never emitted on process.stdin ('data' does not fire; 'end' fires immediately with nothing).
• process.argv has length 1; neither the script path nor arguments after it are present, and I found no CLI syntax that forwards them.

COMPATIBILITY.md lists process.stdin and process.argv as supported. If stdin and argv are intentionally withheld from the isolate, an explicit capability (and a note in the matrix) would make that clear; today the script just sees empty input.

Environment

• Slice v0.10.7, commit ea7c70c, built with cargo +1.96.0 build --release --locked --bin slice
• Reference: Node.js v24.22.2 (same script, same machine)
• Ubuntu 26.04, Linux 7.0, x86_64
• Not checked on v0.10.5.