[XiaoBinGan]

Problem and result

After strata update moved the engine from 0.1.52 to 0.1.54, the model kept launching the old picture reader,
components/engine/0.1.52-.../strata-vision.exe, with no warning (#4658). The run config names the engine as a
component but the picture reader as an absolute path into one engine folder, and with_current_reader() only replaced
that path when it was gone — which it is not, because an update keeps the old engine folder.

After the change the reader follows the engine, the way strata.exe does:

[strata] the picture reader C:\...\components\engine\0.1.52-windows-x86_64-cuda-cuda13\strata-vision.exe
belongs to an engine that is no longer the one in use; using C:\...\components\engine\0.1.54-windows-x86_64-cuda-cuda13\strata-vision.exe
from the engine package in use

Related discussion

#4658 — the report, with the run config excerpt and the cause. No separate scope agreement was asked for: this is a bug
in the existing "use the reader of the package in use" path, not a new feature.

Approach

with_current_reader(cfg, package) had one condition — not os.path.exists(old). It now also remaps when the path sits
in another engine package folder:

def _in_another_engine_package(path: str, package: Path) -> bool:
    if "components" not in [part.lower() for part in Path(path).parent.parts] or \
            "engine" not in [part.lower() for part in Path(path).parent.parts]:
        return False
    try:
        return Path(path).parent != package
    except (OSError, ValueError):
        return False

• Only the components/engine/<version>/ layout counts. A reader the person put somewhere else (the Q8_0 encoder
  docs describe pointing at one) is left untouched, so no custom setup is rewritten.
• The current package's own reader is left alone; nothing changes when nothing is stale.
• The missing-path case keeps its old message and behaviour.
• cpu_exe goes through the same loop, so it follows too.

Validation

Passed: python -m pytest serve/test_server.py -q on this checkout (Python 3.11.16, Windows): 358 passed, 3
skipped, 516 subtests passed. The four new cases in CurrentReader pass: a reader in an old engine package is
replaced even though it still exists; a missing reader is still replaced; a reader outside components/engine/ is left
alone (same object returned); the current package's reader is left alone.

Passed: the A/B — with serve/server.py reverted to main, the new case fails with
AssertionError (serve/test_server.py:6308), so the tests pin the change rather than passing by themselves.

Failed: none.

Not run: a real strata update across two engine versions on this machine. The report's evidence is the run config
it quotes; the change is the path decision it describes, and the tests drive that decision with real directories. I did
not reproduce the full update flow.

Limits

• The remap is by file name inside the current package (strata-vision, or strata-vision-hip from cpu_exe). If a
  future engine package ships the reader under a different name, the remap finds no file and leaves the old path, as
  today.
• Only exe and cpu_exe are considered, the two keys the run config carries for the reader.
• strata update itself still does not rewrite run configs; this fixes the read side, which is where every start goes
  through. A config left stale on disk is corrected in memory each time, not written back.