Issue specifying linux platform constraint to bazel workspace

arpitpatel901 commented 1 year ago

Currently I am attempting to build a starter grpc project with bazel[version 6.3.2]. Upon building, I get the following error, which I believe requires me to add the platform constraints[I believe the default platform is windows, while I am using an ubuntu os]:

ERROR: /home/arpit/.cache/bazel/_bazel_arpit/f196a2da91eeaec415a1459ab74281d6/external/bazel_tools/platforms/BUILD:89:6: in alias rule @bazel_tools//platforms:windows: Constraints from @bazel_tools//platforms have been removed. Please use constraints from @platforms repository embedded in Bazel, or preferably declare dependency on https://github.com/bazelbuild/platforms. See https://github.com/bazelbuild/bazel/issues/8622 for details.

Thus I added the following to my project

inside WORKSPACE

git_repository(
    name = "platforms",
    commit = "33a3b209f94856193266871b1545054afb90bb28",
    remote = "https://github.com/bazelbuild/platforms",
)

I then created a linux_platform.bzl file inside the workspace:

load("@bazel_tools//tools/build_defs:platforms/linux.bzl", "platform")

platform(
    name = "linux",
    constraint_values = {
        "@platforms//os:linux": 1,
    },
)

and then linked the linux_platform file inside my project BUILD file to force the build for linux os:

load("//:linux_platform.bzl", "linux")

However this fails, with the following error:

ERROR: Skipping ':all': while parsing ':all': error loading package 'projects/python_folder/grpc': at /home/arpit/bazel_ws/workspace-template/linux_platform.bzl:1:6: cannot load '@bazel_tools//tools/build_defs:platforms/linux.bzl': no such file

I am new to bazel environment [previously have been using catkin/cmake], so I apologize for the noob question. What am I missing here, I see that linux.bzl is not part of the platforms repo, but I thought should it would built with the os folder. How do I provide the linux constraint ?

aiuto commented 1 year ago

A few things.

Use http_archive to bring in the repo. See https://github.com/bazelbuild/platforms/releases/tag/0.0.8
Never git_repository if you can avoid it.
Do not use load("@bazel_tools//tools/build_defs:platforms/linux.bzl", "platform"). You should use the native platform() rule. Avoid any use of things in @bazel_tools because we are eliminating more from it at each Bazel release.
But, in general you do not have to create platforms if you are building for the machine type you are running on.
If you are trying to build for linux from Windows, then you might need to define that, but you will also need a suitable cross-compiler.

arpitpatel901 commented 1 year ago

Thanks @aiuto for the quick response ! :)

That is weird since I am building for ubuntu and running it on ubuntu too :/ I changed the import to use http

http_archive(
    name = "platforms",
    urls = [
        "https://mirror.bazel.build/github.com/bazelbuild/platforms/releases/download/0.0.8/platforms-0.0.8.tar.gz",
        "https://github.com/bazelbuild/platforms/releases/download/0.0.8/platforms-0.0.8.tar.gz",
    ],
    sha256 = "8150406605389ececb6da07cbcb509d5637a3ab9a24bc69b1101531367d89d74",
)

Removed links to linux.bz[load] in my project build file and directly used the native platform format:

platform(
    name = "linux_x86",
    constraint_values = [
        "@platforms//os:linux",
        "@platforms//cpu:x86_64",
        ":glibc_2_25",
    ],
)

But still for some reason, during build it is trying to build for windows[did a bazel clean --expunge in the middle]:

arpit@arpit-ThinkPad-T460s:~/bazel_ws/workspace-template/projects/python_folder/grpc$ bazel build :all
Starting local Bazel server and connecting to it...
DEBUG: Rule 'com_google_absl' indicated that a canonical reproducible form can be obtained by modifying arguments commit = "215105818dfde3174fe799600bb0f3cae233d0bf" and dropping ["tag"]
DEBUG: Repository com_google_absl instantiated at:
  /home/arpit/bazel_ws/workspace-template/WORKSPACE:48:15: in <toplevel>
Repository rule git_repository defined at:
  /home/arpit/.cache/bazel/_bazel_arpit/f196a2da91eeaec415a1459ab74281d6/external/bazel_tools/tools/build_defs/repo/git.bzl:181:33: in <toplevel>
ERROR: /home/arpit/.cache/bazel/_bazel_arpit/f196a2da91eeaec415a1459ab74281d6/external/bazel_tools/platforms/BUILD:89:6: in alias rule @bazel_tools//platforms:windows: Constraints from @bazel_tools//platforms have been removed. Please use constraints from @platforms repository embedded in Bazel, or preferably declare dependency on https://github.com/bazelbuild/platforms. See https://github.com/bazelbuild/bazel/issues/8622 for details.
ERROR: /home/arpit/.cache/bazel/_bazel_arpit/f196a2da91eeaec415a1459ab74281d6/external/bazel_tools/platforms/BUILD:89:6: Analysis of target '@bazel_tools//platforms:windows' failed
ERROR: /home/arpit/.cache/bazel/_bazel_arpit/f196a2da91eeaec415a1459ab74281d6/external/upb/BUILD:83:11: errors encountered resolving select() keys for @upb//:upb
ERROR: Analysis of target '//projects/python_folder/grpc:helloworld_py_grpc' failed; build aborted: 
INFO: Elapsed time: 18.628s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (82 packages loaded, 1327 targets configured)
    Fetching repository @python_interpreter; starting
    Fetching repository @boringssl; starting
    Fetching ...81d6/external/boringssl; Extracting b9232f9e27e5668bc0414879dcdedb2a59ea75f2.tar.gz
    Fetching ...f196a2da91eeaec415a1459ab74281d6/external/python_interpreter; Extracting python.tar
arpit@arpit-ThinkPad-T460s:~/bazel_ws/workspace-template/projects/python_folder/grpc$

This is how I am loading the grpc library

Inside project WORKSPACE file:

http_archive(
    name = "com_github_grpc_grpc",
    strip_prefix = "grpc-1.45.0",
    sha256 = "ec19657a677d49af59aa806ec299c070c882986c9fcc022b1c22c2a3caf01bcd",
    urls = ["https://github.com/grpc/grpc/archive/refs/tags/v1.45.0.tar.gz"],
)
load("@com_github_grpc_grpc//bazel:grpc_deps.bzl", "grpc_deps")
grpc_deps()
load("@com_github_grpc_grpc//bazel:grpc_extra_deps.bzl", "grpc_extra_deps")
grpc_extra_deps()

and then inside the project BUILD:

load("@rules_proto//proto:defs.bzl", "proto_library")
load("@com_github_grpc_grpc//bazel:python_rules.bzl", "py_grpc_library", "py_proto_library")

Is there something wrong/outdated with my grpc imports ?

arpitpatel901 commented 1 year ago

I was able to solve the platform windows issue by following instructions from https://rules-proto-grpc.com/en/latest/lang/python.html#python-proto-compile for writing a grpc protobuf. This particular issue is solved. Thank you !

bazelbuild / platforms

Issue specifying linux platform constraint to bazel workspace #80