ci: use the fallback resolver for deps

Author: cuviper

ci/test_full.sh

@@ -21,6 +21,14 @@ check_version() {
   ]]
 }
 
+export CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS=fallback
+generate_lockfile() {
+  cargo generate-lockfile
+  if ! check_version 1.85 ; then
+    cargo +stable update
+  fi
+}
+
 echo "Testing $CRATE on rustc $RUST_VERSION"
 if ! check_version $MSRV ; then
   echo "The minimum for $CRATE is rustc $MSRV"
@@ -30,11 +38,7 @@ fi
 FEATURES=()
 echo "Testing supported features: ${FEATURES[*]}"
 
-cargo generate-lockfile
-
-# num-traits 0.2.19 started using dep: features, which requires 1.60 and is
-# otherwise ignored down to 1.51, but we need a manual downgrade before that.
-check_version 1.51 || cargo update -p num-traits --precise 0.2.18
+generate_lockfile
 
 set -x