docs(buglog): log worker signal and launch-type issues (bug-1954..bug-1956)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.wolf/bugs/bug-1954.md

@@ -0,0 +1,69 @@
+---
+id: "bug-1954"
+status: "open"
+status_updated: "2026-10-10"
+status_note: "newly logged"
+component: "worker"
+severity: "wrong-result"
+timestamp: "2026-10-10T08:46:07Z"
+last_seen: "2026-10-10T08:46:07Z"
+occurrences: 1
+files: ["src/worker/src/xcecd_worker.c"]
+tags: ["worker", "job-control", "signal"]
+related: ["bug-1940"]
+---
+
+# bug-1954: xcecd_worker sends SIGTERM for a KILL request without force and SIGSTOP for a TSTP request
+
+## Description
+**Observed:** (source reading, 2026-10-10; found while fixing bug-1940)
+`worker_signal_callback()` (`src/worker/src/xcecd_worker.c:1115-1130`)
+replaces the requested signal:
+```c
+case SIGTERM:
+case SIGKILL:
+    if (force) { success = signal_gid_except_self(SIGKILL); }
+    else       { success = signal_gid_except_self(SIGTERM); }
+...
+case SIGSTOP:
+case SIGTSTP:
+    success = signal_gid_except_self(SIGSTOP);
+```
+Since bug-1940 the requested signal reaches the worker, but an explicit
+`kill -s KILL` without force still sends SIGTERM, and an explicit TSTP is sent
+as the uncatchable SIGSTOP.
+
+**Expected:** the job receives the signal the user asked for; force kill
+(SIGKILL) stays available for a default kill.
+**Impact:** wrong result: a job that ignores SIGTERM survives an explicit
+SIGKILL request; a job that handles SIGTSTP to checkpoint or clean up cannot
+do so.
+**Found by:** review of the bug-1940/1942 fixes, 2026-10-10.
+## Environment
+- OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
+- libc: glibc 2.42-47 (interpreter /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47/lib/ld-linux-x86-64.so.2)
+- Toolchain: gcc (GCC) 15.2.0, meson 1.9.1
+- Build: asan (xce.build)
+- Code: scheduler-framework @ 8568c8ab-dirty
+- Deployment: real `xcecd` worker (systemd/dbus); multi-host for the remote-task case
+
+## Reproduction
+1. Run a job that traps TERM (`trap '' TERM; sleep 600`).
+2. `POST /xce/v1/jobs/<id>/control` with action kill, signal `SIGKILL`,
+   force_kill false.
+3. The job keeps running (it received SIGTERM).
+- Frequency: deterministic by code reading (not yet run)
+- Evidence: the code quoted in Description; no logs kept.
+## Root cause
+TODO: required for fixed/partial
+
+## Fix
+TODO: required for fixed/partial
+
+## Verification
+- Test: TODO: name + file; RED before the fix, GREEN after
+- Suites: TODO: suite results and build profile
+- Live: TODO: soak/deploy run, or n/a and why
+
+## References
+- Related: none