layout: posts

title: Bazel 0.5.0 Released

We are delighted to announce the [0.5.0 release of

Bazel](https://github.com/bazelbuild/bazel/releases/tag/0.5.0) (follow the link

for the full release notes and list of changes).

This release simplifies Bazel installation on Windows and platforms where a JDK

is not available. It solidifies the Build Event Protocol and [Remote Execution

APIs](https://docs.google.com/document/d/1AaGk7fOPByEvpAbqeXIyE8HX_A3_axxNnvroblTZ_6s/edit).

As announced earlier, when using an install script, bazel now comes by default

bundled with JDK 8. This means fewer steps required to install Bazel. Read more

about JDK 7 deprecation in [the related blog

post](https://bazel.build/blog/2017/04/21/JDK7-deprecation.html).

Bazel on Windows is now easier to install: it is no longer linked with MSYS. A

following blog post will detail this further. Bazel is now able to build Java,

C++ and Python on Windows.

The [Build Event

Protocol](https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/buildeventstream/proto/build_event_stream.proto)

is now available as an experimental option; it enables programmatic subscription

to Bazel's events (build started, action status, target completed, test

results…). Currently, the protocol can only be written to a file. A gRPC

transport is already in the works and will be added in the next minor release.

The API will be stabilized in 0.5.1.

Use bazel coverage //my:target to generate coverage information from a

java\_test.

New rules in Bazel:

[proto\_library](https://bazel.build/versions/master/docs/be/protocol-buffer.html#proto_library),

[java\_lite\_proto\_library](https://bazel.build/versions/master/docs/be/java.html#java_lite_proto_library),

[java\_proto\_library](https://bazel.build/versions/master/docs/be/java.html#java_proto_library)

and

[cc\_proto\_library](https://bazel.build/versions/master/docs/be/c-cpp.html#cc_proto_library).

There is a new repository for building for Apple platforms:

[https://github.com/bazelbuild/rules\_apple](https://github.com/bazelbuild/rules_apple).

These rules replace the deprecated iOS/watchOS rules built into Bazel. By

rebuilding the rules from the ground up in Skylark and hosting them separately,

we can more quickly fix bugs and implement new Apple features and platform

versions as they become available.

- Integration with the Android Support Repository libraries in

android\_sdk\_repository.

- Support for Java 8 in Android builds with --experimental\_desugar\_for\_android.

See [Android Studio's

documentation](https://developer.android.com/studio/preview/features/java8-support.html)

for more details about Android's Java 8 language features.

- Multidex is now fully supported via

[android\_binary.multidex](https://bazel.build/versions/master/docs/be/android.html#android_binary.multidex).

- android\_ndk\_repository now supports Android NDK 13 and NDK 14.

- APKs are now signed with both APK Signature V1 and V2.

See [Android

documentation](https://source.android.com/security/apksigning/v2.html) for more

details about APK Signature Scheme v2.

We fixed a number of bugs in the Remote Execution implementation. The final RPC

API design has been sent to

[bazel-discuss@](https://groups.google.com/forum/#!forum/bazel-discuss) for

discussion (see [Design Document: Remote Execution

API](https://docs.google.com/document/d/1AaGk7fOPByEvpAbqeXIyE8HX_A3_axxNnvroblTZ_6s/edit#heading=h.ole76l21af90))

and it should be finalized in the 0.6.0 release. The final API should only be a

minor change compared to the implementation in this 0.5.0 release.

- Declared Providers are now implemented and

[documented](https://bazel.build/versions/master/docs/skylark/rules.html#providers).

They enable more robust and clearly defined interfaces between different

rules and aspects. We recommend using them for all rules and aspects.

- The type formerly known as 'set' is now called 'depset'. Depsets make your

rules perform much better, allowing rules memory consumption to scale

linearly instead of quadratically with build graph size - make sure you have

read the

[documentation on depsets](https://bazel.build/versions/master/docs/skylark/depsets.html).

A big thank you to our community for your continued support.

Particular shout-outs to Peter Mounce for the [Chocolatey Windows

package](https://bazel.build/versions/master/docs/install-windows.html) and Yuki

Yugui Sonoda for maintaining [rules\_go](https://github.com/bazelbuild/rules_go)

(they both received an [open source peer

bonus](https://opensource.googleblog.com/2017/03/the-latest-round-of-google-open-source.html)

from Google).

Thank you all, keep the

[questions](http://stackoverflow.com/questions/tagged/bazel) and [bug

reports](https://github.com/bazelbuild/bazel/issues) coming!

\---

- Bazel's Linux sandbox no longer mounts an empty tmpfs on /tmp,

instead the existing /tmp is mounted read-write. If you prefer

to have a tmpfs on /tmp for sandboxed actions for increased

hermeticity, please use the flag --sandbox\_tmpfs\_path=/tmp.

- Converting artifacts to strings and printing them now return

"File" instead of "Artifact" to be consistent with the type name.

- The return type of depset.to\_list() is now a list rather than a

frozen list. (Modifying the list has no effect on the depset.)

- Bazel now prints logs in single lines to java.log

- --use\_dash, --dash\_url and --dash\_secret are removed.

- Remote repositories must define any remote repositories they

themselves use (e.g., if @x//:foo depends on @y//:bar, @y must be

defined

in @x's WORKSPACE file).

- Remote repositories must define any remote repositories they

themselves use (e.g., if @x//:foo depends on @y//:bar, @y must be

defined

in @x's WORKSPACE file).

- objc\_xcodeproj has been removed, use tulsi.bazel.build instead.

- If grte\_top is a label, it can now follow non-configurable

redirects.

- Optional coverage\_files attribute to cc\_toolchain

- "query --output=build" now includes select()s

- Raw LLVM profiles are now supported.

- Automatically generate Proguard mapping when resource shrinking

and Proguard are enabled.

- New rules in Bazel: proto\_library, java\_lite\_proto\_library,

java\_proto\_library and cc\_proto\_library

- Activate the "dead\_strip" feature if objc binary stripping is

enabled.

- More stable naming scheme for lambda classes in desugared android

code

- Convert --use\_action\_cache to a regular option

- Per-architecture dSYM binaries are now propagated by

apple\_binary's AppleDebugOutputsProvider.

- Avoid factory methods when desugaring stateless lambdas for

Android

- desugar calls to Objects.requireNonNull(Object o) with

o.getClass() for android

- Add an --copy\_bridges\_from\_classpath argument to android

desugaring tool

- Change how desugar finds desugared classes to have it working on

Windows

- Evaluation of commands on TargetsBelowDirectory patterns

(e.g. //foo/...) matching packages that fail to load now report

more

detailed error messages in keep\_going mode.

- Allow to have several inputs and outputs

- Repository context's execute() function can print stdout/stderr

while running. To enable, pass quiet=False.

- Bazel can now be built with a bundled version of the OpenJDK.

This makes it possible to use Bazel on systems without a JDK, or

where

the installed JDK is too old.

- The --jobs flag now defaults to "auto", which causes Bazel to

use a reasonable degree of parallelism based on the local

machine's

capacity.

- Bazel benchmark (perf.bazel.build) supports Java and Cpp targets.

- no factory methods generated for lambda expressions on android

- The Linux sandbox no longer changes the user to 'nobody' by

default, instead the current user is used as is. The old behavior

can be

restored via the --sandbox\_fake\_username flag.

- /tmp and /dev/shm are now writable by default inside the

Linux sandbox.

- Bazel can now use the process-wrapper + symlink tree based

sandbox implementation in FreeBSD.

- turn on --experimental\_incremental\_dexing\_error\_on\_missed\_jars by

default.

- All android\_binarys are now signed with both Apk Signature V1 and

V2. See https://source.android.com/security/apksigning/v2.html

for more details.

- Windows MSVC wrappers: Not filtering warning messages anymore,

use --copt=-w and --host\_copt=-w to suppress them.

- A downloader bug was fixed that prevented RFC 7233 Range

connection resumes from working with certain HTTP servers

- Introduces experimental android\_device rule for configuring and

launching Android emulators.

- For boolean flags, setting them to false using --no\_<flag\_name>

is deprecated. Use --no<flag\_name> without the underscore, or

--<flag\_name>=false instead.

- Add --experimental\_android\_compress\_java\_resources flag to store

java

resources as compressed inside the APK.

- Removed --experimental\_use\_jack\_for\_dexing and libname.jack

output of

android\_library.

- blaze canonicalize-flags now takes a --show\_warnings flag

- Changing --invocation\_policy will no longer force a server

restart.

- Bazel now supports Android NDK14.

- android\_binary multidex should now work without additional flags.

- Use action\_config in crosstool for static library archiving,

remove ar\_flag.

- new option for bazel canonicalize-flags, --canonicalize\_policy

- Use action\_config in crosstool for static library archiving,

remove ar\_flag.

- android\_library exports\_manifest now defaults to True.

- Fix select condition intersections.

- Adds a --override\_repository option that takes a repository

name and path. This forces Bazel to use the directory at that path

for the repository. Example usage:

`--override_repository=foo=/home/user/gitroot/foo`.

- fix idempotency issue with desugaring lambdas in interface

initializers for android

- --experimental\_android\_use\_singlejar\_for\_multidex is now a no-op

and will eventually be removed.

- Every local\_repository now requires a WORKSPACE file.

- Remove jack and jill attributes of the android\_sdk rule.

- Add Skylark stubs needed to remove sysroot from CppConfiguration.

- Desugar try-with-resources so that this language feature is

available

to deveces with API level under 19.

- The flag --worker\_max\_retries was removed. The

WorkerSpawnStrategy no longer retries execution of failed Spawns,

the reason being that this just masks compiler bugs and isn't

done for any other execution strategy either.

- Bazel will no longer gracefully restart workers that crashed /

quit, instead this triggers a build failure.

- All java resources are now compressed in android\_binary APKs by

default.

- All java resources are now compressed in android\_binary APKs by

default.

- android\_ndk\_repository now creates a cc\_library

(@androidndk//:cpufeatures) for the cpufeatures library that is

bundled in the Android NDK. See

https://developer.android.com/ndk/guides/cpu-features.html for

more details.

- 'output\_groups' and 'instrumented\_files' cannot be specified in

DefaultInfo.

- You can increase the CPU reservation for tests by adding a

"cpu:<n>" (e.g. "cpu:4" for four cores) tag to their rule in a

BUILD file. This can be used if tests would otherwise overwhelm

your system if there's too much parallelism.

- Deprecate use\_singlejar\_for\_proguard\_libraryjars and force

behavior to always on.