From cbf79cdc8e2be93c1c6fd62013073cb917efbc3b Mon Sep 17 00:00:00 2001
From: Zack Winter <3457246+zackwintermdb@users.noreply.github.com>
Date: Wed, 28 Jan 2026 10:29:22 -0800
Subject: [PATCH] SERVER-118037: Hydrate Unit Test Cache (#47094)

GitOrigin-RevId: a11242a482722f6114d3c3f0b57cf6c263b8123f
---
 .bazelrc                                      |  1 +
 .../tasks/compile_tasks.yml                   | 22 +++++++++++++++++++
 evergreen/bazel_compile.sh                    |  7 +++++-
 evergreen/bazel_test.sh                       |  7 +++++-
 4 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/.bazelrc b/.bazelrc
index 36b50af3bfd..21ae003da95 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -442,6 +442,7 @@ common:remote_unittest --cache_test_results=auto
 common:remote_unittest --dev_stacktrace=False
 common:remote_unittest --run_under=//bazel:test_wrapper
 common:remote_unittest --test_timeout=660
+common:remote_unittest --define GIT_COMMIT_HASH=nogitversion
 test:remote_unittest --test_tag_filters=mongo_unittest,-intermediate_debug,-incompatible_with_bazel_remote_test
 
 # Coverage
diff --git a/etc/evergreen_yml_components/tasks/compile_tasks.yml b/etc/evergreen_yml_components/tasks/compile_tasks.yml
index ecbcdcea8d3..51b6a4cf7cc 100644
--- a/etc/evergreen_yml_components/tasks/compile_tasks.yml
+++ b/etc/evergreen_yml_components/tasks/compile_tasks.yml
@@ -300,6 +300,27 @@ tasks:
             --keep_going
             --build_tag_filters=${bazel_filters_for_cache_hydration}
 
+  - name: hydrate_bazel_unit_tests
+    tags:
+      [
+        "assigned_to_jira_team_devprod_build",
+        "bazel_cache_hydration",
+        "auxiliary",
+      ]
+    depends_on:
+      - name: version_expansions_gen
+        variant: generate-tasks-for-version
+    commands:
+      - func: "bazel test"
+        vars:
+          compiling_for_test: true
+          test_timeout_sec: 660 # Allow extra 60s for coredump on abort
+          no_mongo_version: true
+          targets: //src/mongo/...
+          bazel_args: >-
+            --config=remote_unittest
+            --keep_going
+
   - name: run_bazel_clang_tidy
     tags:
       [
@@ -1314,6 +1335,7 @@ task_groups:
       - hydrate_bazel_profile_dbg
       - hydrate_bazel_profile_dbg_aubsan
       - hydrate_bazel_profile_dbg_tsan
+      - hydrate_bazel_unit_tests
 
   - <<: *compile_task_group_template
     name: hydrate_all_headers_TG
diff --git a/evergreen/bazel_compile.sh b/evergreen/bazel_compile.sh
index cdbfe389359..bb5e6229d14 100755
--- a/evergreen/bazel_compile.sh
+++ b/evergreen/bazel_compile.sh
@@ -117,8 +117,13 @@ LOCAL_ARG="$(bazel_evergreen_shutils::maybe_release_flag "$LOCAL_ARG")"
 # Ensure server is up and print PID
 bazel_evergreen_shutils::ensure_server_and_print_pid "$BAZEL_BINARY"
 
+MONGO_VERSION_ARG="--define=MONGO_VERSION=${version}"
+if [[ -n "${no_mongo_version}" ]]; then
+    MONGO_VERSION_ARG=""
+fi
+
 # Build flags line
-ALL_FLAGS="--verbose_failures ${LOCAL_ARG} --define=MONGO_VERSION=${version} ${bazel_args:-} ${bazel_compile_flags:-} ${task_compile_flags:-} ${patch_compile_flags:-}"
+ALL_FLAGS="--verbose_failures ${LOCAL_ARG} ${MONGO_VERSION_ARG} ${bazel_args:-} ${bazel_compile_flags:-} ${task_compile_flags:-} ${patch_compile_flags:-}"
 echo "${ALL_FLAGS}" >.bazel_build_flags
 
 # Save the entire bazel build invocation to attach to the task for re-running locally
diff --git a/evergreen/bazel_test.sh b/evergreen/bazel_test.sh
index 31a4c71b4f1..6dba17bdd1f 100644
--- a/evergreen/bazel_test.sh
+++ b/evergreen/bazel_test.sh
@@ -34,8 +34,13 @@ LOCAL_ARG="$(bazel_evergreen_shutils::maybe_release_flag "$LOCAL_ARG")"
 # Possibly scale test timeout and append to bazel_args
 bazel_evergreen_shutils::maybe_scale_test_timeout_and_append
 
+MONGO_VERSION_ARG="--define=MONGO_VERSION=${version}"
+if [[ -n "${no_mongo_version}" ]]; then
+    MONGO_VERSION_ARG=""
+fi
+
 # Build the shared flags and persist the --config subset
-ALL_FLAGS="--verbose_failures ${LOCAL_ARG} --define=MONGO_VERSION=${version} ${bazel_args:-} ${bazel_compile_flags:-} ${task_compile_flags:-} ${patch_compile_flags:-}"
+ALL_FLAGS="--verbose_failures ${LOCAL_ARG} ${MONGO_VERSION_ARG} ${bazel_args:-} ${bazel_compile_flags:-} ${task_compile_flags:-} ${patch_compile_flags:-}"
 echo "${ALL_FLAGS}" >.bazel_build_flags
 
 # to capture exit codes