Release Notes — v0.6.4¶

rtkrcv Stability Fixes + Community Profile¶

Release date: 2026-04-16 Type: Patch — rtkrcv crash fixes + GitHub Community Profile completion Branch: release/v0.6.4

Overview¶

v0.6.4 is a patch release dominated by rtkrcv stability fixes. It ships three independently root-caused crashes that affected the mrtk run (rtkrcv) status path, plus the repository-hygiene work that completes MRTKLIB's GitHub Community Profile (issue/PR templates, declarative labels, CONTRIBUTING, SECURITY, and Code of Conduct).

No positioning-engine behavior changes. No new public APIs. The 62-test CTest suite passes unchanged.

rtkrcv stability fixes (user-facing)¶

Fix — status-poll SIGSEGV from out-of-bounds mode[] read (#74)¶

prstatus() had an 8-entry mode[] array but newer positioning modes (PMODE_PPP_RTK=9, PMODE_VRS_RTK=12, …) had been added since, so the second status poll in any PPP-RTK / VRS-RTK session read past the array end and crashed on the invalid pointer. Mode table is now 13 entries covering PPP-fixed, PPP-RTK, SSR2OSR, SSR2OSR-fixed, and VRS-RTK, with bounds checks on both mode[] and freq[].

Commit: 5daa212

Fix — status-poll data race on shared state vectors (#74)¶

prstatus() shallow-copied rtk_t under the server lock, leaving the x / P / xa / Pa pointers aliased to heap buffers that the processing thread kept mutating via rtkpos(). The race window was ~50–200 ms/epoch in PPP-RTK mode and surfaced as intermittent SIGSEGVs during long runs.

Fix: extract the values the status path actually needs (position + covariance diagonal) into local variables while the lock is held, then null out the shared pointers after unlock so the status path cannot chase them. A SIGSEGV backtrace handler plus -rdynamic on Linux was added to make any future crashes easier to post-mortem.

Commit: 1656081

Fix — async-signal-safe SIGSEGV handler that preserves core dumps (#82, #85)¶

The new crash handler originally called fprintf() (not async-signal-safe) and _exit() (which suppresses core dumps). It now uses write(2) for diagnostics, reinstalls the default signal handler, and re-raises the signal so OS core-dump capture still fires. Review rounds on #85 tightened the handler further.

Commits: e352c24, 4dd6b62, 6e507d0

Repository hygiene — GitHub Community Profile¶

v0.6.4 also lands the intake-surface work that activates MRTKLIB's GitHub Community Profile. These changes do not affect the compiled artifact.

• Issue and PR templates (#88) — five issue templates (bug_report, positioning_issue, feature_request, documentation, question), a PR template with ctest slot and positioning-regression check, and .github/ISSUE_TEMPLATE/config.yml pointing at the docs site.
• Declarative labels + sync workflow (#90) — .github/labels.yml is now the single source of truth for the 34-label scheme (type / module / mode / gnss / priority / status). EndBug/label-sync runs on push to main when labels.yml changes.
• Policy documents (#92) — CONTRIBUTING.md (issue reporting, fork + upstream workflow, coding standards, positioning-regression guard), SECURITY.md (Private Vulnerability Reporting; scope also explicitly covers Code of Conduct reports), and CODE_OF_CONDUCT.md (Contributor Covenant 2.1 verbatim).

Additional: README now links the CLAS real-time Grafana dashboard for users monitoring mrtk run telemetry.

Files Changed¶

Upgrade notes¶

• rtkrcv users on v0.6.3 or earlier — upgrading is recommended. The mode-table out-of-bounds fix (#5daa212) affects anyone running mrtk run in PPP-RTK or VRS-RTK mode and polling status.
• No configuration, TOML schema, or API changes. Existing rtkrcv.toml / rnx2rtkp invocations run unchanged.

Test Results¶

62/62 tests pass (no regressions).