[Bug] Sub-agent fork context inheritance causes excessive token consumption and unresumable transcripts
Bug Description
Main session (34M):
/home/brad/.claude/projects/-home-brad-DevOps-Personal-Strategies-Understanding-Larger-Codebases/b373f1d6-003a-4d8f-817b-fed9c42369b4.jsonl
Sub-agent runs (31M):
/tmp/claude-1000/-home-brad-DevOps-Personal-Strategies-Understanding-Larger-Codebases/b373f1d6-003a-4d8f-817b-fed9c42369b4/tasks/
The specific things worth citing, since they're the reproducible ones:
The fork defect — subagent_type: "fork" inherits the full parent context, so a fork spawned to summarise a GitHub thread consumed 143,790 tokens for work costing ~2k directly. Two others returned
garbled, truncated output and could not be resumed (No transcript found) after 26 minutes and ~476k tokens. Sub-agents chose to fork for this despite explicit "YOU SPAWN NOTHING" instructions.
Agents stalling mid-task — a validator armed a background timer, reported "completed", posted nothing, and did it twice across ~490k tokens.
Silent completion without delivery — three lanes landed commits to qa-kube and finished without writing to their issue, so the code shipped and the reasoning was lost.
Those are platform behaviours. The orchestration failures on top of them were mine — recommending 22 concurrent lanes I couldn't track, and reporting "staffed" as if it meant "converted." I'd
include that in the report too; it's part of an honest picture.
I'm not spawning anything further. One lane remains — the #217/#225/#227 validator, now partly redundant since #217 closed. Say the word and I'll stop it.
Environment Info
- Platform: linux
- Terminal: pycharm
- Version: 2.1.233
- Feedback ID: 9ced8743-394a-4dd1-a35b-27abc21a6f8c
Errors
[{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: <html>\r\n<head><title>502 Bad Gateway</title></head>\r\n<body>\r\n<center><h1>502 Bad Gateway</h1></center>\r\n<hr><center>openresty</center>\r\n<p><em>Powered by <a href=\"https://apisix.apache.org/\">APISIX</a>.</em></p></body>\r\n</html>\r\n\n at send (/$bunfs/root/cli:18779:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-16T05:15:34.427Z"},{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: <html>\r\n<head><title>502 Bad Gateway</title></head>\r\n<body>\r\n<center><h1>502 Bad Gateway</h1></center>\r\n<hr><center>openresty</center>\r\n<p><em>Powered by <a href=\"https://apisix.apache.org/\">APISIX</a>.</em></p></body>\r\n</html>\r\n\n at send (/$bunfs/root/cli:18779:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-16T05:15:35.236Z"}]This issue has 1 comment on GitHub. Read the full discussion on GitHub ↗