Fix #10459: Support .bazelversion files without a trailing newline.
This brought up the question of how to handle a completely empty .bazelversion file. I checked what Bazelisk does in this case (silently assume that the latest stable Bazel version should be used, just as if you explicitly write "latest" into the file). Thus we slightly change the behavior of the wrapper to more closely match the behavior of Bazelisk, which will help to reduce user confusion.
RELNOTES: None.
PiperOrigin-RevId: 294438748
diff --git a/scripts/packages/bazel.sh b/scripts/packages/bazel.sh
index cf101a1..1b353b9 100755
--- a/scripts/packages/bazel.sh
+++ b/scripts/packages/bazel.sh
@@ -106,27 +106,44 @@
readonly os_arch_suffix="$(uname -s | tr '[:upper:]' '[:lower:]')-$(uname -m)"
function get_bazel_version() {
+ bazel_version=""
+
if [[ -n ${USE_BAZEL_VERSION:-} ]]; then
- readonly reason="specified in \$USE_BAZEL_VERSION"
- readonly bazel_version="${USE_BAZEL_VERSION}"
+ reason="specified in \$USE_BAZEL_VERSION"
+ bazel_version="${USE_BAZEL_VERSION}"
elif [[ -e "${workspace_dir}/.bazelversion" ]]; then
- readonly reason="specified in ${workspace_dir}/.bazelversion"
- read -r bazel_version < "${workspace_dir}/.bazelversion"
- readonly bazel_version="${bazel_version}"
- elif [[ -x "${wrapper_dir}/bazel-real" ]]; then
- readonly reason="automatically selected bazel-real"
- readonly bazel_version="real"
- else
- # Find the latest Bazel version installed on the system.
- readonly reason="automatically selected latest available version"
- bazel_version="$(basename "$(find -H "${wrapper_dir}" -maxdepth 1 -name 'bazel-[0-9]*-${os_arch_suffix}' -type f | sort -V | tail -n 1)")"
- if [[ -z $bazel_version ]]; then
- bazel_version="$(basename "$(find -H "${wrapper_dir}" -maxdepth 1 -name 'bazel-[0-9]*' -type f | sort -V | tail -n 1)")"
- fi
- # Remove the "bazel-" prefix from the file name.
- bazel_version="${bazel_version#"bazel-"}"
- readonly bazel_version
+ reason="specified in ${workspace_dir}/.bazelversion"
+ # The "read" can fail if the .bazelversion file does not contain a final
+ # newline character. It will still correctly assign the read data to the
+ # variable. Of course it can also fail due to real I/O errors. Because we do
+ # validation of the read data later, we can just ignore the error here.
+ # Alternatives like 'bazel_version=$(head -1 ...)' are not better either,
+ # because bash does not care about the exit code of processes used in
+ # command substitution.
+ read -r bazel_version < "${workspace_dir}/.bazelversion" || true
fi
+
+ # If we read an empty string or the magic word "latest" from .bazelversion or
+ # $USE_BAZEL_VERSION, then we should use the latest available stable version.
+ # This mimics the behavior of Bazelisk.
+ if [[ -z $bazel_version || $bazel_version == "latest" ]]; then
+ if [[ -x "${wrapper_dir}/bazel-real" ]]; then
+ reason="${reason:-"automatically selected bazel-real"}"
+ bazel_version="real"
+ else
+ # Find the latest Bazel version installed on the system.
+ reason="${reason:-"automatically selected latest available version"}"
+ bazel_version="$(basename "$(find -H "${wrapper_dir}" -maxdepth 1 -name 'bazel-[0-9]*-${os_arch_suffix}' -type f | sort -V | tail -n 1)")"
+ if [[ -z $bazel_version ]]; then
+ bazel_version="$(basename "$(find -H "${wrapper_dir}" -maxdepth 1 -name 'bazel-[0-9]*' -type f | sort -V | tail -n 1)")"
+ fi
+ # Remove the "bazel-" prefix from the file name.
+ bazel_version="${bazel_version#"bazel-"}"
+ fi
+ fi
+
+ readonly reason
+ readonly bazel_version
}
get_bazel_version
diff --git a/src/test/shell/bazel/bazel_wrapper_test.sh b/src/test/shell/bazel/bazel_wrapper_test.sh
index fea3b57..f22ae7e 100755
--- a/src/test/shell/bazel/bazel_wrapper_test.sh
+++ b/src/test/shell/bazel/bazel_wrapper_test.sh
@@ -103,6 +103,26 @@
expect_log "My args: build //src:bazel"
}
+test_empty_bazelversion_file() {
+ setup_mock
+
+ touch .bazelversion
+ ../bin/bazel info &> "$TEST_log"
+ expect_log "Hello from bazel-real"
+
+ echo "" > .bazelversion
+ ../bin/bazel info &> "$TEST_log"
+ expect_log "Hello from bazel-real"
+}
+
+test_explicit_latest_bazel() {
+ setup_mock
+
+ echo "latest" > .bazelversion
+ ../bin/bazel info &> "$TEST_log"
+ expect_log "Hello from bazel-real"
+}
+
test_uses_bazelreal() {
setup_mock
@@ -255,4 +275,15 @@
expect_log "My args:"
}
+# Regression test for https://github.com/bazelbuild/bazel/issues/10459
+test_bazelversion_without_newline() {
+ setup_mock
+
+ echo -n "1.0.1" > .bazelversion
+
+ ../bin/bazel info &> "$TEST_log"
+ expect_log "Hello from bazel-1.0.1"
+ expect_log "My args: info"
+}
+
run_suite "Integration tests for scripts/packages/bazel.sh."
