Merge rust-bitcoin#5028: Use recent lock file when checking API files

e8c42a7 Use recent lock file when checking API files (Tobin C. Harding)

Pull request description:

  Recently we added `--locked` to all the `cargo` invocations in the script to check API text files. But if one has an updated lock file (newer than recent) then this achieves nothing. I.e., if one has run `cargo` _without_ `--locked` then the local lock file will have deps that are too new (*cough* serde I'm looking at you).
  
  Copy the recent lock file into place when the script is run locally but preserve the lock file state once the script is finished running.


ACKs for top commit:
  apoelstra:
    ACK e8c42a7; successfully ran local tests


Tree-SHA512: 032238d30db2afa87c44b5a77e870b0052e96c2bdf76b18ba00a642c929ef859a7da9966213e0d21c572e34039a137cb5876af45f3f3481c44b0640384e38fb7

Author: apoelstra

contrib/check-for-api-changes.sh

@@ -24,9 +24,18 @@ main() {
     need_nightly
     need_cargo_public_api
 
+    # If script is running in CI the recent lock file is copied into place
+    # already by the github action job. Locally be kind to the environment.
+    if [ "${GITHUB_ACTIONS:-}" != "true" ]; then
+        [ -f "Cargo.lock" ] && mv Cargo.lock Cargo.lock.tmp
+        cp Cargo-recent.lock Cargo.lock
+    fi
+
     # Just check crates that are stabilising.
     generate_api_files "units"
 
+    [ -f "Cargo.lock.tmp" ] && mv Cargo.lock.tmp Cargo.lock
+
     check_for_changes
 }