Case 84: Multi-library bundle SONAME skew¶

Field	Value
Verdict	🔴 BREAKING
Category	Breaking
Platforms	Linux
Flags	ABI break, Bad practice
Detected `ChangeKind`s	`bundle_soname_skew`
Source files	browse on GitHub

Category: Cross-artifact ABI | Verdict: BREAKING

What breaks¶

oneDAL ships as a co-versioned bundle:

libonedal_core.so.X
libonedal_thread.so.X
libonedal_sequential.so.X
libonedal_parameters.so.X
libonedal_dpc.so.X
libonedal_sycl.so.X

They are intended to move SONAME in lockstep. The break case84 encodes: release engineering bumps five of the six (.so.1 → .so.2) but libonedal_thread.so.1 keeps the old SONAME by accident. Each library on its own passes per-library ABI checks. The bundle does not:

Distro packages declare Depends: libonedal-core2, libonedal-thread1 — internally inconsistent.
A binary linked against v1 finds libonedal_thread.so.1 (still installed) and libonedal_core.so.2 (the only one available) — the two were built against different internal contracts, leading to corruption at the first cross-library call.

Layout¶

Unlike the other cases, this one has no single v1.cpp/v2.cpp pair. Instead v1 and v2 are directories containing multiple .so files:

case84_bundle_soname_skew/
├── v1/
│   ├── libonedal_core.so.1
│   ├── libonedal_thread.so.1
│   └── libonedal_dpc.so.1
└── v2/
    ├── libonedal_core.so.2
    ├── libonedal_thread.so.1   <-- soname-laggard
    └── libonedal_dpc.so.2

The compare-release mode of abicheck ingests both directories and runs the cross-library aggregator.

Why this is its own ChangeKind¶

Existing soname_changed and soname_bump_recommended are per-library signals. The skew is a property of the set of libraries; no individual artifact is wrong. A new BUNDLE_SONAME_SKEW ChangeKind in BREAKING_KINDS reports the cohort-level invariant: "five siblings bumped, one did not."

How abicheck detects it¶

abicheck/bundle_soname.py runs after compare-release collects per-pair results. It extracts each library's SONAME major from both releases, clusters libraries by a configurable cohort prefix (default: longest common prefix among bundle members), and emits one BUNDLE_SONAME_SKEW finding when a cohort has mixed soname deltas (some bumped, some not).

Source files for the example: see gen_bundle.sh for the script that produces the .so files. The CMake integration wires this up under the abicheck_add_bundle_case macro.

Case 84: Multi-library bundle SONAME skew¶

What breaks¶

Layout¶

Why this is its own ChangeKind¶

How abicheck detects it¶

Source files¶