The shell has a line limit nobody wrote down, and it refuses in Go's words

Status

Open

Found while

answering a question about storing 10 MB files as 2 KB rows

Triage

Defer

Component

server

What was measured

An invoke typed into the operator shell with a value about a megabyte long:

main> invoke chunk.put id=big/1048576 b=aaaa…
  bufio.Scanner: token too long

The limit is real and deliberate — internal/cli/shell.go builds its reader with lines.Buffer(make([]byte, 0, 64<<10), 1<<20), so a line may be up to 1 MiB and no further. Nothing on that path is broken.

What is wrong with it

The refusal names a Go standard-library type. It does not say there is a line limit, what the limit is, that it belongs to the shell rather than to the store, or that the same value would be accepted by a client. An operator reading it learns that something inside the program is called bufio.Scanner.

This project treats a refusal as documentation — the learn site says as much, and ISS-21 was opened because a refusal reached a caller as "failed". This is the same shape one layer out: the message is accurate to the implementation and useless to the reader.

It is also the only limit of its kind that is not written down. A value has no declared maximum at all, which is SAPE-31's problem; this one is a maximum that exists, applies only to one entry point, and is invisible until it fires.

Why Defer

It loses no data, breaks no promise on a public surface, and stops nobody installing or running anything. The value is refused, not truncated — the write does not happen, and the operator can see it did not. A client is unaffected: the limit is the shell's line reader and nothing else.

What closing it would mean

• A refusal in the product's own words, naming the limit, saying it belongs to the shell, and pointing at the client for a value that size.
• Deciding whether 1 MiB is the right number now that one plausible use — base64 rows for a large file — has appeared. That is a smaller decision than it looks: the rows in that design are 2 KB.
• A note wherever the shell is documented, because a limit that only appears when it fires is a limit nobody can plan around.

Out of scope

• Any limit on a value in the store. There is none, and adding one is SAPE-31's size posture, not this.
• Reading a value from a file rather than a line. That is a different shell feature and nobody has asked for it.