cargo publish does not work without --no-verify

[freshtonic]

cargo publish claims that the source directory was modified during the build and does not create the release tarball.

You can reproduce locally (without risking publishing it) by running cargo publish --dry-run.

The code generation step does not write to the src directory (just to OUT_DIR, like a well-behaved build.rs).

error: failed to verify package tarball

Caused by:
  Source directory was modified by build.rs during cargo publish. Build scripts should not modify anything outside of OUT_DIR.
  Added: <snip>/sqltk/target/package/sqltk-0.1.0/Cargo.lock

  To proceed despite this, pass the `--no-verify` flag.

Assuming that the file on the Added: line is the culprit, a diff of that file (which is in the target subdir) with the version in the project dir shows no changes.

They also have identical checksums.

Very mysterious.