Merge commit '9fd9aa46' into 2022-10--update-elements (PR #454)

PR 454: Pin serde to 1.0.142

Didn't test this one; it only affects test.sh

Author: apoelstra

contrib/test.sh

@@ -4,6 +4,15 @@ set -e
 
 FEATURES="compiler serde rand"
 
+# Use toolchain if explicitly specified
+if [ -n "$TOOLCHAIN" ]
+then
+    alias cargo="cargo +$TOOLCHAIN"
+fi
+
+cargo update -p serde --precise 1.0.142
+cargo update -p serde_derive --precise 1.0.142
+
 cargo --version
 rustc --version