Bazel 5/6/7 compatibility

.bazelrc

@@ -1,10 +1,13 @@
 build --color=yes
+build --cxxopt=-std=c++20
 build --incompatible_strict_action_env
 build --keep_going
+common --noenable_bzlmod  # This line is automatically removed in CI for Bazel 5
 test --announce_rc
 test --keep_going
 test --spawn_strategy=sandboxed
 test --test_env=NO_CLEANUP=1
 test --test_env=PYTEST_ADDOPTS="--color=yes --capture=tee-sys --tb=short --showlocals -ra --verbose --verbose"
+test --test_env=USE_BAZEL_VERSION  # Pass this on to tests to enable adapting to bazel-version specific behavior
 test --test_output=errors
 test --test_verbose_timeout_warnings

.bazelversion

@@ -1 +1 @@
-6.4.0
+7.x

.github/workflows/ci.yaml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        bazel-version: ["5.x", "6.x", "latest"]
+        bazel-version: ["5.x", "6.x", "7.x"]
         os: ["ubuntu-latest", "macos-latest"]
 
     steps:
@@ -25,7 +25,8 @@ jobs:
           path: "~/.cache/bazelisk\n~/.cache/bazel\n"
           key: bazel-${{ matrix.bazel-version }}-cache-${{ github.run_id }}
           restore-keys: bazel-${{ matrix.bazel-version }}-cache-
-      - run: sed -i.bak '/remove if Bazel version < 6/d' tests/test.cc && rm tests/test.cc.bak
+
+      - run: sed -i.bak '/enable_bzlmod/d' .bazelrc && rm .bazelrc.bak
         if: ${{ startsWith(matrix.bazel-version, '5') }}
 
       - run: bazel test //...

tests/BUILD

@@ -64,7 +64,7 @@ py_binary(
         ":external_bin.appimage",
         ":symlink_and_emptyfile",
     ],
-    env = {"MY_BINARY_ENV": "not propagated by rules_python :("},
+    env = {"MY_BINARY_ENV": "propagated only in Bazel 7+"},
     main = "test.py",
 )
 

tests/appimage_test_cc_with_sh_test.sh

@@ -2,4 +2,6 @@
 
 set -eux
 
-exec env --ignore-environment "tests/appimage_test_cc" --appimage-extract-and-run
+exec env --ignore-environment \
+    USE_BAZEL_VERSION="${USE_BAZEL_VERSION:-latest}" \
+    "tests/appimage_test_cc" --appimage-extract-and-run

tests/test.cc

@@ -9,18 +9,25 @@ int main(int argc, char** argv, char** envp) {
   // When running inside the appimage, we want the env to not be lost.
   bool have_binary_env = false;
   bool have_appimage_env = false;
+  std::string bazel_version{"unknown"};
   for (char** env = envp; *env != 0; env++) {
-    char* thisEnv = *env;
+    std::string thisEnv{*env};
     std::cout << thisEnv << std::endl;
-    if (std::string(thisEnv) == "MY_BINARY_ENV=not lost") {
+    if (thisEnv == "MY_BINARY_ENV=not lost") {
       have_binary_env = true;
-    } else if (std::string(thisEnv) == "MY_APPIMAGE_ENV=overwritten") {
+    } else if (thisEnv == "MY_APPIMAGE_ENV=overwritten") {
       have_appimage_env = true;
+    } else if (thisEnv.starts_with("USE_BAZEL_VERSION=")) {
+      bazel_version = thisEnv.substr(18);
     }
   }
   if (!have_binary_env) {
     std::cerr << "MY_BINARY_ENV not found or has wrong value" << std::endl;
-    return EXIT_FAILURE;  // remove if Bazel version < 6
+    if (bazel_version.starts_with("5")) {
+      // This is only expected to work in Bazel 6+
+    } else {
+      return EXIT_FAILURE;
+    }
   }
   if (!have_appimage_env) {
     std::cerr << "MY_APPIMAGE_ENV not found or has wrong value" << std::endl;

tests/test.py

@@ -88,9 +88,15 @@ def test_runfiles_symlinks() -> None:
 
 def test_binary_env() -> None:
     """Test that env attr on the binary target is handled."""
-    # Unfortunately rules_python does not seem to set the RunEnvironmentInfo provider.
-    # See https://github.com/bazelbuild/rules_python/issues/901
-    assert "MY_BINARY_ENV" not in os.environ
+    bazel_version = os.getenv("USE_BAZEL_VERSION", "latest")
+    if bazel_version.startswith(("latest", "7.")):
+        # Bazel >= 7.0.0 does set the RunEnvironmentInfo provider 🎉.
+        assert os.getenv("MY_BINARY_ENV") == "propagated only in Bazel 7+"
+    else:
+        # Otherwise it seems rules_python does not set the RunEnvironmentInfo provider.
+        # See https://github.com/bazelbuild/rules_python/issues/901
+        val = os.getenv("MY_BINARY_ENV")
+        assert val is None, f"Expected env to be missing, but got {val}"
 
 
 def greeter() -> None: