Fix CircleCI issues with Cargo.lock format incompatibility.
Seems like there is an incompatibility with the Cargo.lock files generated between older and newer versions of Rust (most likely the new merge-friendly format), which is affecting CircleCI in recent PRs (see #75).
This commit should hopefully allow us to start with an old lockfile, test our changes on stable, and then subsequently upgrade to the new lockfile format with nightly.
Fixed
Cargo.lock
format incompatibility.Seems like there is an incompatibility with the
Cargo.lock
files generated between older and newer versions of Rust (most likely the new merge-friendly format), which is affecting CircleCI in recent PRs (see #75).This commit should hopefully allow us to start with an old lockfile, test our changes on stable, and then subsequently upgrade to the new lockfile format with nightly.