Enable spec shaking v2 by default

[leighmcculloch]

What

Add experimental_spec_shaking_v2 to the default feature set in soroban-sdk, enabling the feature by default.

Why

So far feedback is either neutral or positive.

The feature significantly improves the spec shaking process of the sdk.

Spec shaking v2 has been available as an experimental feature last month. The v26 release candidate will be created soon, and then it will become stable in 1 month. In total that provides approx 50 days for the experimental feature to be available for developers to provide feedback.

The feature name with its experimental_ prefix is preserved for backwards compatibility and will be removed in v27 when v2 becomes the only spec shaking implementation supported.

If negative feedback arises while v26 is in release candidate we can revisit the roll out. While v26 is in stable people can still disable v2 if needed if edge cases are discovered, and the final roll out targeting v27 can be delayed if needed.

[Copilot]

Pull request overview

This PR enables spec shaking v2 by default in soroban-sdk, updating tests and CI workflows to treat v2 as the baseline behavior while keeping v1 available via default-features = false.

Changes:

• Add experimental_spec_shaking_v2 to soroban-sdk’s default feature set.
• Update spec shaking test crates so v2 uses defaults and v1 explicitly disables default features.
• Simplify external-repo CI workflows by removing the v1/v2 feature-matrix testing.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
soroban-sdk/Cargo.toml	Enables spec shaking v2 via default features.
soroban-sdk/src/_features.rs	Updates feature docs to reflect v2 default and v1 opt-out.
tests/spec_shaking_v2/Cargo.toml	Removes explicit v2 feature flag since it’s now default.
tests/spec_shaking_v1/Cargo.toml	Disables default features to keep v1 behavior.
.github/workflows/test-with-soroban-examples.yml	Removes v2 toggle matrix and related patching steps.
.github/workflows/test-with-openzeppelin-stellar-contracts.yml	Removes v2 toggle matrix and related patching steps.

Comments suppressed due to low confidence (1)

tests/spec_shaking_v1/Cargo.toml:20

• [dependencies] disables default features to force spec shaking v1, but [dev-dependencies] reintroduces soroban-sdk without default-features = false. Because Cargo unifies features for the same dependency across dependency kinds when running tests, this can end up enabling the default feature set (and therefore spec shaking v2) for this crate’s cargo test build, undermining the intent of the v1 test setup. Consider adding default-features = false to the [dev-dependencies] soroban-sdk entry as well (while still enabling testutils).

soroban-sdk = {path = "../../soroban-sdk", default-features = false}
test_spec_lib = {path = "../spec_lib"}

[dev-dependencies]
soroban-sdk = {path = "../../soroban-sdk", features = ["testutils"]}
soroban-spec = {path = "../../soroban-spec"}