Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.203 Home All releases olderv2.1.202 v2.1.204newer

Stdin Unreadable: Helpful Warning Instead of Silent Failure

When stdin is unreadable (e.g., the process was launched without a proper stdin pipe), Claude Code now emits a clear warning and continues rather than failing silently:

"Warning: stdin is unreadable (<reason>), proceeding without piped input. If you piped input, it was not received — pass it as a prompt argument, or check that the process launching Claude Code wires stdin to a pipe or /dev/null."

Evidence

Stdin error handler (search for "pass it as a prompt argument, or check that the process launching Claude Code wires stdin to a pipe or /dev/null")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.203 →