docs(buglog): bug-1926 sim REPL break jobid= filter ignores dashed jobids

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

2026-10-08 16:08:54 +00:00

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bug-1926: xce_scheduler --sim REPL break jobid= filter ignores the dashed jobid form the REPL prints

Description

Observed: a break DECISION jobid=<id> (or break <EVENT> jobid=<id>) breakpoint set with the dashed jobid form the REPL itself prints never fires. With the 1.1 contention fixture:

[sim] breakpoint 1 set: DECISION jobid=0-0-0-104
-- (continue runs to the end; no hit)
[sim] breakpoint 1 set: DECISION jobid=104
[sim] hit breakpoint 1 @ decision: PEND jobid=0-0-0-104

The hit line prints jobid=0-0-0-104, yet only the raw decimal packed id (jobid=104) matches. The breakpoint is accepted without any warning.

Expected: a jobid filter accepts the same jobid forms the REPL prints and info job accepts (parse_jobid/parse_jobsel, including X[k] array elements), as well as the raw decimal id.

Impact: wrong result, usability. An operator copies a jobid from REPL output into break ... jobid=, and the breakpoint silently never stops the run. For real jobids (non-zero cluster/user/time fields) the raw decimal form is a large number nobody types, so jobid breakpoints are effectively unusable. No effect on scheduling.

Found by: spec task scheduler-sim-decision-trace 6.1 (end-to-end tests had to use raw decimal ids for breakpoints), confirmed by the 6.1 review. It predates that feature: repl_u64_str_eq comes from commit 2fecea35 (2026-08-07).

Suspected: repl_u64_str_eq() (src/scheduler/src/repl_break.c:210) formats the packed jobid with %llu and compares strings, so only the decimal form can match. It is used by the decision filter (repl_decision_matches_filter, ~line 346) and, per its comment, by every jobid= filter including event filters.

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 @ 4d1a245f-dirty
Deployment: none (offline xce_scheduler --sim <replay> --interactive)

Reproduction

Build the scheduler: bash src/tools/xce-build.sh scheduler (ASAN, src/xce.build).
sh /home/claude/tmp/bug-1926/repro.sh /home/rshen/projects/xce/scheduler-framework. It runs the committed fixture src/scheduler/testsuite/fixtures/repl_trace_baseline/contention.replay with the script break DECISION jobid=<sel>, continue, quit, once with sel=0-0-0-104 and once with sel=104.
The dashed form prints only the "breakpoint 1 set" line; the decimal form also prints "hit breakpoint 1 @ decision: PEND jobid=0-0-0-104".

Frequency: deterministic (1/1 each, 2026-10-08)
Evidence: /home/claude/tmp/bug-1926/ (repro.sh, repro.out)

Root cause

TODO: required for fixed/partial

Fix