Detailed steps to reproduce the problem?

The Go driver parses runOnRequirements.csfle.minLibmongocryptVersion from the Unified Test Format but never enforces it. Tests that should be skipped when the loaded libmongocrypt is too old instead run and fail with confusing low-level errors.

CSFLEOptions.MinVer (bson:"minLibmongocryptVersion") is never read anywhere in non-test code.

Set csfle.minLibmongocryptVersion to "99.99.99" in QE-Text-prefix.json, run TestUnifiedSpec for that file with the cse tag against a 9.0 server:

go test -tags cse -run TestUnifiedSpec/client-side-encryption/tests/unified/QE-Text-prefix ./internal/integration/...

The test runs and fails with a cryptographic or server error rather than being skipped.

Definition of done: what must be done to consider the task complete?

verifyRunOnBlockConstraint compares the loaded libmongocrypt version against rob.Options.MinVer and returns an error if it doesn't satisfy the constraint

The exact Go version used, with patch level:

go version go1.25.5 darwin/arm64

The exact version of the Go driver used:

2.6.1, master

Describe how MongoDB is set up. Local vs Hosted, version, topology, load balanced, etc.

The operating system and version (e.g. Windows 7, OSX 10.8, ...)

osx

Security Vulnerabilities

NA