[CLI] copilot --resume "Name With Spaces" fails silently with exit 1

[JoeBrockhaus]

Summary

copilot --resume "<name>" fails with exit code 1 and no output whenever <name> contains spaces, even when the name is an exact, case-correct match for an existing session created via --name. Names without spaces (e.g. kebab-case) resolve correctly.

This contradicts the documented usage in copilot --help:

# Resume a session by name
$ copilot --resume="my feature"

That example cannot work today.

Version

• Copilot CLI 1.0.61
• Windows 11, PowerShell 7
• Launched via the agency wrapper (the standard Windows install)

Reproduction

Resuming with the command copilot provides after /exit

But with just copilot --resume:

# 1. Create a session with a spaced name
copilot --name "Spaced Name Session" -p "echo init" --allow-all-tools --no-ask-user
# exit 0, session created. workspace.yaml shows: name: Spaced Name Session

# 2. Resume by that exact name
copilot --resume "Spaced Name Session" -p "echo go" --allow-all-tools --no-ask-user
# Observed: exit 1, no stdout, no stderr.

Control (changes only one variable — removing the spaces):

copilot --name "UnspacedSession" -p "echo init" --allow-all-tools --no-ask-user
copilot --resume "UnspacedSession" -p "echo go" --allow-all-tools --no-ask-user
# Observed: exit 0, session resumes correctly.

Both --resume "Name" and --resume="Name" forms fail identically for the spaced case. Failure also reproduces against a real long-running session whose name contains spaces.

Expected

Either:

1. Spaced names resolve correctly (matching the documented example), OR
2. The CLI emits a clear error explaining the lookup failed and exits non-zero.

Current silent exit with no diagnostic output sends users down the wrong debugging path: shell quoting, terminal lock, session in-use, version skew. Each of those is a plausible suspect for an exit-1-with-no-output failure.

Workarounds (none acceptable as a fix)

• copilot --resume <7-char-id-prefix> works but defeats the purpose of friendly names
• copilot --resume (interactive picker) works but requires UI interaction
• Rename to kebab-case works but loses readability

Why this matters

The documented and expected workflow for users who name sessions with descriptive labels (the example in --help is literally "my feature") is broken. Every user who follows the docs hits a wall. The silent failure mode multiplies the cost.

[abedbagram-stack]

copilot --name "UnspacedSession" -p "echo init" --allow-all-tools --no-ask-user
copilot --resume "UnspacedSession" -p "echo go" --allow-all-tools --no-ask-user

Observed: exit 0, session resumes correctly.