Better version mismatch messages

[Parth]

When I add the following to my WORKSPACE file (only thing in that file),

rules_scala_version="a89d44f7ef67d93dedfc9888630f48d7723516f7" # I have tried a handful of versions here, same result

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
    name = "io_bazel_rules_scala",
    strip_prefix = "rules_scala-%s" % rules_scala_version,
    type = "zip",
    url = "https://github.com/bazelbuild/rules_scala/archive/%s.zip" % rules_scala_version,
)

load("@io_bazel_rules_scala//scala:toolchains.bzl", "scala_register_toolchains")
scala_register_toolchains()

load("@io_bazel_rules_scala//scala:scala.bzl", "scala_repositories")
scala_repositories()

protobuf_version="66dc42d891a4fc8e9190c524fd67961688a37bbe"
protobuf_version_sha256="983975ab66113cbaabea4b8ec9f3a73406d89ed74db9ae75c74888e685f956f8"

http_archive(
    name = "com_google_protobuf",
    url = "https://github.com/protocolbuffers/protobuf/archive/%s.tar.gz" % protobuf_version,
    strip_prefix = "protobuf-%s" % protobuf_version,
    sha256 = protobuf_version_sha256,
)

I see:

ERROR: /private/var/tmp/_bazel_parth.mehrotra/f3d049f4cd59e2f8a0b016862811f8be/external/io_bazel_rules_scala/scala/scala.bzl:111:13: cfg must be either 'host' or 'target'.
ERROR: /private/var/tmp/_bazel_parth.mehrotra/f3d049f4cd59e2f8a0b016862811f8be/external/io_bazel_rules_scala/scala/scala.bzl:125:22: Traceback (most recent call last):
        File "/private/var/tmp/_bazel_parth.mehrotra/f3d049f4cd59e2f8a0b016862811f8be/external/io_bazel_rules_scala/scala/scala.bzl", line 125
                _common_attrs.update(_common_attrs_for_plugin_bootstr...)
        File "/private/var/tmp/_bazel_parth.mehrotra/f3d049f4cd59e2f8a0b016862811f8be/external/io_bazel_rules_scala/scala/scala.bzl", line 125, in _common_attrs.update
                _common_attrs_for_plugin_bootstrapping
global variable '_common_attrs_for_plugin_bootstrapping' is referenced before assignment.
ERROR: /private/var/tmp/_bazel_parth.mehrotra/f3d049f4cd59e2f8a0b016862811f8be/external/io_bazel_rules_scala/scala/scala.bzl:186:5: Traceback (most recent call last):
        File "/private/var/tmp/_bazel_parth.mehrotra/f3d049f4cd59e2f8a0b016862811f8be/external/io_bazel_rules_scala/scala/scala.bzl", line 185
                _scala_library_for_plugin_bootstrapping_attrs.update(_common_attrs_for_plugin_bootstr...)
        File "/private/var/tmp/_bazel_parth.mehrotra/f3d049f4cd59e2f8a0b016862811f8be/external/io_bazel_rules_scala/scala/scala.bzl", line 186, in _scala_library_for_plugin_bootstrapping_attrs.update
                _common_attrs_for_plugin_bootstrapping
global variable '_common_attrs_for_plugin_bootstrapping' is referenced before assignment.
ERROR: error loading package '': Extension file 'scala/scala.bzl' has errors
ERROR: error loading package '': Extension file 'scala/scala.bzl' has errors
INFO: Elapsed time: 2.416s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (0 packages loaded)

[johnynek]

what version of bazel did you try?

[Parth]

Build label: 0.27.0
Build target: bazel-out/darwin-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Mon Jun 17 13:03:58 2019 (1560776638)
Build timestamp: 1560776638
Build timestamp as int: 1560776638

[johnynek]

It may be that we don't work with 0.27 yet... CI is testing with 0.23: https://github.com/bazelbuild/rules_scala/blob/master/.travis.yml#L23

[Parth]

That was it!

[Parth]

Thank you!

[Parth]

Maybe we should rename the title and re-open with the intention of providing better error reporting to users?

Something like This is the wrong version would go a long way, as this sort of error was un-googlable.

[ittaiz]

@anchlovi @or-shachar did we encounter this issue? We’re just now upgrading to 0.27 and I don’t think we’ve seen this.

…

On Wed, 19 Jun 2019 at 2:31 Parth Mehrotra ***@***.***> wrote: Reopened #771 <#771>. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#771>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAKQQF5JUY3W3WFINLTSK33P3FV43ANCNFSM4HZDYU4A> .

[anchlovi]

We didn't

[ittaiz]

@Parth AFK so not sure, did you use an up to date version of rules_scala? Trying to understand if we just need to update the docs or rules scala itself

[Parth]

Basically all I did was brew install bazel (this downloaded 0.27 by default, I'm sure anyone new to bazel will do something similar), and then attempted to do the most minimal hello world and failed to do so. I tried a handful of hashes, none seemed to work.

The other scala rules guys plan to add this message: "The requested Bazel version '$bazel_version' is not supported" though their's failed to tell me anything useful at the current moment.