v0.16.6

v0.16.5 cannot run on any Sigil 0.17 runtime. It imports the stdlib module (sigil dotenv), which exists only in Sigil 0.18 and later, but it was published on the 0.16 line where every ^0.16 pin resolves to it. Any project on a 0.17 runtime that relocked after 2026-07-28 picked up a sigil-mcp that builds cleanly and then fails at startup.

This release restores the 0.16 line. Its source is identical to v0.16.4, which uses (sigil env) and works on 0.17 runtimes. It exists purely so that ^0.16 resolves to something that runs.

Changes

• Reverts the (sigil env) to (sigil dotenv) migration on the 0.16 line. Source is byte-identical to v0.16.4.
• No other changes.

Upgrade notes

If you are on a Sigil 0.17 runtime, take this release. No pin change is needed: ^0.16 resolves here automatically because 0.16.6 is the newest 0.16.x.

Lowering your pin is NOT a workaround. A range like ^0.16.4 still resolves to 0.16.5, because the caret selects the highest match in the 0.16 line. Only a version above 0.16.5 escapes it, which is what this release is for.

If you have already relocked onto 0.16.5 and your service fails at startup with

    module-import: library not found: (sigil dotenv)

then relocking against this release fixes it.

Verified as a matched pair on a real consumer, same 0.17.12 runtime with isolated cache and store, only the sigil-mcp version differing:

    sigil-mcp 0.16.5  ->  Error loading entry module: library not found: (sigil dotenv)
    sigil-mcp 0.16.4  ->  apiary 0.17.3 (sigil 0.17.12)

Projects running Sigil 0.18 or newer should move to sigil-mcp v0.17.0 instead.