Make target's env higher priority than --run_env

Similar to env + --test_env, --run_env should be a lower priority than
the env directly in the BUILD file.

RELNOTES[inc]: fix --run_env order to prioritize BUILD env over command line

Closes bazelbuild#26887.

PiperOrigin-RevId: 805748782
Change-Id: I327c3ce7d159b8c82ebb6785a7490d30ca805fa7

Author: keith

src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java

@@ -656,7 +656,7 @@ private static RunCommandLine getCommandLineInfo(
     TreeMap<String, String> runEnvironment = makeMutableRunEnvironment(env);
     HashSet<String> envVariablesToClear = new HashSet<>();
     ImmutableMap<String, String> clientEnv = env.getClientEnv();
-    actionEnvironment.resolve(runEnvironment, clientEnv);
+    // Process --run_env flags first
     for (var envVar : extraRunEnvironment) {
       switch (envVar) {
         case Converters.EnvVar.Set(String name, String value) -> {
@@ -680,6 +680,8 @@ private static RunCommandLine getCommandLineInfo(
         }
       }
     }
+    // Then let the target's environment override --run_env flags
+    actionEnvironment.resolve(runEnvironment, clientEnv);
 
     return constructCommandLine(
         env,

src/test/shell/integration/run_test.sh

@@ -813,6 +813,9 @@ EOF
 
 function test_run_env() {
   add_rules_shell "MODULE.bazel"
+  add_to_bazelrc "run --run_env=OVERRIDDEN_RUN_ENV=OVERRIDDEN_VALUE_FROM_BAZELRC"
+  add_to_bazelrc "run --run_env=FROM_BAZELRC=VALUE_FROM_BAZELRC"
+  add_to_bazelrc "run --run_env=FROM_BAZELRC_THEN_UNUSET=VALUE_FROM_BAZELRC"
   local -r pkg="pkg${LINENO}"
   mkdir -p "${pkg}"
   cat > "$pkg/BUILD" <<'EOF'
@@ -834,6 +837,8 @@ set -euo pipefail
 
 echo "FROMBUILD: '$FROMBUILD'"
 echo "OVERRIDDEN_RUN_ENV: '$OVERRIDDEN_RUN_ENV'"
+echo "FROM_BAZELRC: '$FROM_BAZELRC'"
+echo "FROM_BAZELRC_THEN_UNUSET: '${FROM_BAZELRC_THEN_UNUSET:=<unset>}'"
 echo "RUN_ENV_ONLY: '$RUN_ENV_ONLY'"
 echo "EMPTY_RUN_ENV: '$EMPTY_RUN_ENV'"
 echo "INHERITED_RUN_ENV: '$INHERITED_RUN_ENV'"
@@ -849,13 +854,16 @@ EOF
       --run_env=EMPTY_RUN_ENV= \
       --run_env=INHERITED_RUN_ENV \
       --run_env==REMOVED_RUN_ENV \
+      --run_env==FROM_BAZELRC_THEN_UNUSET \
       --run_env=SET_UNSET_SET=set1 \
       --run_env==SET_UNSET_SET \
       --run_env=SET_UNSET_SET=set2 \
       "//$pkg:foo" >"$TEST_log" || fail "expected run to succeed"
 
   expect_log "FROMBUILD: '1'"
-  expect_log "OVERRIDDEN_RUN_ENV: 'FOO'"
+  expect_log "OVERRIDDEN_RUN_ENV: '2'"
+  expect_log "FROM_BAZELRC: 'VALUE_FROM_BAZELRC'"
+  expect_log "FROM_BAZELRC_THEN_UNUSET: '<unset>'"
   expect_log "RUN_ENV_ONLY: 'BAR'"
   expect_log "EMPTY_RUN_ENV: ''"
   expect_log "INHERITED_RUN_ENV: 'BAZ'"
@@ -999,7 +1007,7 @@ EOF
   ./script.bat >"$TEST_log" || fail "expected script to succeed"
 
   expect_log "FROMBUILD: '1'"
-  expect_log "OVERRIDDEN_RUN_ENV: 'FOO'"
+  expect_log "OVERRIDDEN_RUN_ENV: '2'"
   expect_log "RUN_ENV_ONLY: 'BAR'"
 }