ZCode/glm-5.3-flash

* 644cc85  (8 minutes)  <Riza Fahmi>   Release verification: record verified checks and failure diagnostics
* faaa62c  (12 minutes)  <Riza Fahmi>   S7: handle Ctrl-C via wrapper SIGTERM relay with partial summary and exit 130
* 31c83ba  (23 minutes)  <Riza Fahmi>   S6: report elapsed time and completed-response p50/p95
* c70ac56  (31 minutes)  <Riza Fahmi>   S5: report outcome counts and exit 0/1 by completions
* 96908f5  (37 minutes)  <Riza Fahmi>   S4: paced five-second loop with timeout cancellation
* 24c538b  (45 minutes)  <Riza Fahmi>   S3: bounded streaming GET with TLS verification, timeouts, no redirects or retries
* fe53347  (2 hours)  <Riza Fahmi>   S2: validate CLI arguments before any request
* 8e68e2a  (2 hours)  <Riza Fahmi>   S1: launch CLI with cb escript wrapper and help output

1. 191.5% Cost Reduction vs. GLM-5.3 High ($1.10 vs. $12.90) with 6/7 Slices Verified (S5 Incomplete on Live Chunked 301)3 points▸

   • $1.10 Total Run Cost: Running GLM-5.3-Flash with effort: "low" completed the benchmark workflow for $1.10 ($1.1025)—a 91.5% cost reduction compared to GLM-5.3 High ($12.90) on the same ZCode harness.
   • 99.52% Prefix Cache Hit Rate Saved $4.11 (78.8%) Out of 34,374,813 total input tokens across 344 successful turns, 34,210,176 were served from cache (cacheReadTokens) with zero cache invalidations as context grew monotonically from 26,398 to 167,669 tokens.
   • Outside-In TDD Suite (42/42 Local Tests), but S5 Fails Against Live Chunked 301 Responses While the agent's 42 local ExUnit tests passed in 41.4s with zero warnings under mix compile --warnings-as-errors and mix credo --strict, manual S5 verification with ./cb http://rizafahmi.com failed due to a chunked transfer-encoding buffer bug in lib/capy_bench/http.ex.
2. 2S5 Verification Failure on './cb http://rizafahmi.com': Chunked-Body Buffer Drop Causes ':closed' Transport Failures3 points▸

   • Failing Live 301 Redirect Check: Running ./cb http://rizafahmi.com (which returns a Cloudflare HTTP/1.1 301 Moved Permanently response with Transfer-Encoding: chunked) fails 40 of 41 requests with Transport failures: 40 (Failure reasons: :closed: 40 on stderr) instead of counting completed 301 responses.
   • Root Cause in CapyBench.HTTP.read_chunk/5 (lib/capy_bench/http.ex) When reading a chunked body, read_chunk/5 calls read_n(socket, transport, String.to_integer(line, 16) + 2, rest, deadline), which consumes the chunk payload from rest and returns bare :ok—discarding the remaining bytes in rest (including the terminating 0\r\n\r\n chunk that arrived in the same TCP segment)—before calling read_chunked(socket, transport, "", deadline), which then blocks on transport.recv/3 until the server closes the connection ({:error, :closed}).
   • Skipped TodoWrite Updates on S5 & S6: In ZCode's TodoWrite state, the agent marked S5 in_progress at line 273 and never updated TodoWrite after committing S5 (line 290) or S6 (line 317), leaving S5 marked incomplete in the UI todo list until line 362.
3. 3Upstream Stream Instability in S1–S3: 29 'TypeError: terminated' Aborts & 58 Multi-Attempt Retries (~21m Lost)3 points▸

   • 29 Mid-Stream SSE Aborts (10.58m Wasted): Between 18:52 and 20:00 (lines 1–213), 29 LLM responses aborted mid-stream after running for 9.4s to 67.0s each with TypeError: terminated inside Node's undici fetch stream, including a 4-error streak at lines 81–84 that burned 166.1s (2.8m) on a single turn.
   • 58 Multi-Attempt Auto-Retries (~10.2m Unlogged Backoff) Across lines 1–223, 58 turns required internal retries before succeeding (46 on attempt 2, 10 on attempt 3, and 2 on attempt 4 at lines 80 and 145). On the 46 retry turns without a preceding error row, inter-turn gaps after fast local tools totaled 610.2s (10.17m) of unlogged failed-attempt and backoff latency.
   • Complete Recovery After Line 224: Only 2 stream drops required manual 'continue' nudges (lines 102 and 213, plus 1 after a cancelled Bash run at line 358, totaling 87.2s / 1.45m of idle time). From line 224 (20:04) through line 373 (20:44), all 150 final turns across S3–S7 succeeded on attempt 1 with zero stream terminations.
4. 4S3 Consumed 46.5% of Active Time (51.7m, 156 LLM Calls) Due to Five OTP/GenServer Traps4 points▸

   • 1. macOS Keychain Ignores SSL_CERT_FILE (Lines 67–85, ~8m) The agent spent 15 turns probing :public_key.cacerts_get() in /tmp before confirming that OTP on macOS reads the system Keychain and ignores SSL_CERT_FILE, requiring explicit :public_key.cacerts_load(path) when SSL_CERT_FILE is set.
   • 2. Misplacing extra_applications in mix.exs (Lines 127–146, ~7m) At line 128, it added extra_applications: [:logger, :ssl, :public_key, :crypto] inside def project instead of def application, then spent 18 turns investigating why :code.lib_dir(:ssl) returned {:error, :bad_name} under Mix before spotting its mix.exs placement bug at line 145.
   • 3. Four TestServer GenServer Bugs (Lines 103–176, ~22m) In test/support/test_server.ex, it sequentially debugged (a) handling GenServer.call(:request) inside handle_info instead of handle_call (line 117), (b) blocking the GenServer inside :gen_tcp.accept/1 so worker GenServer.call messages timed out (line 149), (c) calling self() inside spawn(fn -> accept(..., self()) end) so workers messaged the acceptor PID instead of the GenServer (line 160), and (d) using GenServer.start_link/2 in TestServer.start/1 which crashed ExUnit teardown after TestServer.stop/1 (line 176).
   • 4. Calling Removed :ssl.accept/2 on OTP 28 (Lines 183–198, ~4m) HTTPS test server connections crashed with UndefinedFunctionError on :ssl.accept/2 until replaced with :ssl.transport_accept/1 + :ssl.handshake/2 at line 195.
5. 55.5 MB erl_crash.dump Committed Four Times via 'git add -A' (877k Diff Lines)2 points▸

   • Broken Pipe Crash Dumps from head/tail Pipelines Piping Mix output into head or tail (such as mix compile 2>&1 | head -8 at line 295) closed stdout early while the BEAM was still writing to :standard_error, triggering an unhandled :badarg (:epipe) during VM termination and writing a 5.5 MB erl_crash.dump to the repo root.
   • Unignored Artifact Staged by git add -A: Because .gitignore only excluded /_build/, /deps/, and /cb.escript (line 31), running git add -A && git commit -q committed erl_crash.dump in S1 (8e68e2a, +215,252 lines) and updated it in S3 (24c538b, 284,165 lines changed), S6 (31c83ba, 205,614 lines changed), and S7 (faaa62c, 272,280 lines changed).
6. 6S7 Signal-Relay & POSIX 'wait' Exit-Status Debugging2 points▸

   • Upfront S1 Probe (Lines 14–27): In /tmp/cbprobe, the agent verified that OTP 28 rejects :os.set_signal(:sigint, :handle) and default escripts ignore SIGINT, then validated swapping :erl_signal_server's handler via :gen_event.swap_handler/3 to catch :sigterm from a ./cb wrapper.
   • Two S7 Integration Bugs Caught Live (Lines 342–353) When testing real Ctrl-C in S7, it fixed (1) CapyBench.SignalHandler.init/1 crashing because :gen_event.swap_handler/3 passes {init_arg, term} rather than bare init_arg (line 344), and (2) the ./cb wrapper's wait loop treating the escript's legitimate exit code 130 (> 128) as an interrupted wait builtin and re-invoking wait $child, which returned 127 (fixed at lines 346–349 via kill -0).
7. 7ZCode File-State Guard Friction (18 Inline Python Patches & 1 Binary Overwrite Error)2 points▸

   • 8 of 14 Edit Errors from Stale Read State: Running mix format or inline scripts invalidated ZCode's file-mtime tracker, causing 8 Edit calls (lines 174, 185, 204, 226, 236, 313, 321, 338) to fail with 'File has been modified since read' and 1 Read call (line 152) to be rejected as a 'Wasted call'. To avoid extra Read turns, the agent executed 18 file mutations via python3 - <<'EOF' inside Bash.
   • Binary Escript Overwrite Guard (Line 28): When converting ./cb from a compiled escript binary to a POSIX shell wrapper in S1, ZCode's Write tool rejected overwriting ./cb with 'Unsupported or binary text encoding', prompting the agent to write the wrapper via cat > cb <<'EOF' in Bash (line 29).
8. 8Low-Effort Reasoning Profile & Clean Git Commit Metadata (No Hallucinated Co-Author)2 points▸

   • Selective Reasoning on effort: "low": Only 140 of 344 successful turns (40.7%) emitted reasoningText (~42.2k estimated thinking tokens, or 40.9% of the 103.0k output tokens), while 204 tactical turns emitted 0 reasoning characters. Architectural turns still scaled up thinking when needed, led by line 5 (S1 plan: 143.8s, 5,474 output tokens) and line 246 (S4 runner: 102.2s, 4,245 output tokens).
   • No Hallucinated Co-Author Trailers: Unlike GLM-5.3 High (which spontaneously appended 'Co-Authored-By: Claude Fable 5' to all 8 commits on the same ZCode harness), GLM-5.3-Flash Low committed cleanly with single-line git commit -q -m messages and zero co-author trailers.