Merge rust-bitcoin/rust-bitcoin#1114: Add ci check for duplicate dependencies

cda097d Add ci check for duplicate dependencies (Tobin C. Harding)

Pull request description:

  Add a call to `cargo tree --duplicates` in the ci script to ensure that we do not have any duplicated dependencies.

  Kudos to Kixunil  for the idea (over in: rust-bitcoin/rust-bitcoin#1104)

ACKs for top commit:
  apoelstra:
    ACK cda097d
  Kixunil:
    ACK cda097d

Tree-SHA512: 77f07dd5c6794b5a59293bd62bda0fe61384a30cf8258e79aca9ce32090f869f0a13929b6a7a4c35e10fc653968b12ddd4c291df9ecd0962632017f59c81d025

Author: apoelstra

contrib/test.sh

@@ -22,6 +22,15 @@ if cargo --version | grep nightly; then
     NIGHTLY=true
 fi
 
+# We should not have any duplicate dependencies. This catches mistakes made upgrading dependencies
+# in one crate and not in another (e.g. upgrade bitcoin_hashes in bitcoin but not in secp).
+duplicate_dependencies=$(cargo tree  --target=all --all-features --duplicates | wc -l)
+if [ "$duplicate_dependencies" -ne 0 ]; then
+    echo "Dependency tree is broken, contains duplicates"
+    cargo tree  --target=all --all-features --duplicates
+    exit 1
+fi
+
 echo "********* Testing std *************"
 # Test without any features other than std first
 cargo test --verbose --no-default-features --features="std"