From c4cb172a2720d381b36c0c301453610b0caebe4c Mon Sep 17 00:00:00 2001
From: Ben Newman <ben@apollographql.com>
Date: Wed, 8 May 2024 14:41:28 -0400
Subject: [PATCH 1/2] Include Git branch in CircleCI cache keys and bump key
 version.

This should resolve an issue affecting the 2.7.5 release, where an old
federation-2/target/ cache was restored from an unrelated PR branch
build (because Cargo.lock was the same), causing the compiled supergraph
binary to call op_composition_result with a string rather than an object
in some cases, triggering a panic on the Rust side.

I would have liked to disable this caching completely when publishing an
official release, to prioritize correctness over build speed, but it
doesn't seem like conditional caching is supported by CircleCI:
https://circleci.com/docs/caching/#clearing-cache

We could potentially run `cargo clean` conditionally for release builds,
after restore_cache (thereby throwing away the cache), but that doesn't
seem ideal.
---
 .circleci/config.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 8852be923..70bf8fa03 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -418,14 +418,14 @@ commands:
     steps:
       - restore_cache:
           keys:
-            - rust-target-v2-<< parameters.platform >>-{{ checksum "Cargo.lock" }}
+            - &target-cache-key rust-target-v3-<< parameters.platform >>-{{ .Branch }}-{{ checksum "Cargo.lock" }}
 
       - run:
           command: cargo xtask << parameters.command >> << parameters.options >>
           working_directory: << parameters.working_directory >>
 
       - save_cache:
-          key: rust-target-v2-<< parameters.platform >>-{{ checksum "Cargo.lock" }}
+          key: *target-cache-key
           paths:
             - target/
 

From eb4feff2d688a5840c3bf52dcc8febdb1d1f6398 Mon Sep 17 00:00:00 2001
From: Ben Newman <ben@apollographql.com>
Date: Fri, 10 May 2024 10:23:31 -0400
Subject: [PATCH 2/2] On second thought, disable CircleCI target/ caching
 altogether.

https://github.com/apollographql/federation-rs/pull/476#pullrequestreview-2046504558
---
 .circleci/config.yml | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 70bf8fa03..303abe6ca 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -416,18 +416,26 @@ commands:
         type: string
         default: ./
     steps:
-      - restore_cache:
-          keys:
-            - &target-cache-key rust-target-v3-<< parameters.platform >>-{{ .Branch }}-{{ checksum "Cargo.lock" }}
+      # After burning two release versions due to caching misbehavior, we've
+      # decided to disable target/ caching for now, since this repository
+      # publishes builds relatively infrequently, and correctness is much more
+      # important than build speed. If build speed does become a problem in the
+      # future, it should be safe to uncomment the restore_cache and save_cache
+      # steps below, since we bumped v2 to v3 and added {{ .Branch }} in PR #476
+      # but never published anything using these rules.
+
+      # - restore_cache:
+      #     keys:
+      #       - &target-cache-key rust-target-v3-<< parameters.platform >>-{{ .Branch }}-{{ checksum "Cargo.lock" }}
 
       - run:
           command: cargo xtask << parameters.command >> << parameters.options >>
           working_directory: << parameters.working_directory >>
 
-      - save_cache:
-          key: *target-cache-key
-          paths:
-            - target/
+      # - save_cache:
+      #     key: *target-cache-key
+      #     paths:
+      #       - target/
 
       - when:
           condition: