No matching toolchains found for types @bazel_tools//tools/cpp:toolchain_type

[fcorange]

Hitting below error when trying out the example on mac:

ERROR: While resolving toolchains for target @dbx_build_tools//build_tools/py:check_conflicts: No matching toolchains found for types @bazel_tools//tools/cpp:toolchain_type. Maybe --incompatible_use_cc_configure_from_rules_cc has been flipped and there is no default C++ toolchain added in the WORKSPACE file? See https://github.com/bazelbuild/bazel/issues/10134 for details and migration instructions.

Some googling suggests that this might be related to Bazel remote execution. Is this expected?

FYI I had to revert the python 3.7 removal commit, otherwise getting below error:

no such target '@dbx_build_tools//thirdparty/cpython:drte-off-38-toolchain': target 'drte-off-38-toolchain' not declared in package 'thirdparty/cpython' (did you mean 'drte-off-37-toolchain'?)

[armooo]

I think part of the problem could be the README.md pinning a version from Dec 11 but was updated to use python38. What version of dbx_build_tools and bazel are you using?

[fcorange]

I was following the README here https://github.com/dropbox/dbx_build_tools/blob/master/README.md

I tried both latest Bazel (3.5.1) and 1.1.0, both returned similar errors.

[armooo]

Can you give this WORKSPACE a try? If it works I will make sure to update the README.

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "dbx_build_tools",
    urls = ["https://github.com/dropbox/dbx_build_tools/archive/master.tar.gz"],
    strip_prefix = "dbx_build_tools-master",
)

load('@dbx_build_tools//build_tools/bazel:external_workspace.bzl', 'drte_deps')

drte_deps()

register_toolchains(
    "@dbx_build_tools//thirdparty/cpython:drte-off-27-toolchain",
    "@dbx_build_tools//thirdparty/cpython:drte-off-38-toolchain",
)

[fcorange]

No luck :( still hitting the first error I mentioned above. Tried on both Bazel 1.1.0 and 3.5.1. Guess I'll just input my issue to bazelbuild/bazel#10134. Thanks for looking though!

[benjaminp]

I think we would have to know all the Bazel options in play to debug this.

[fcorange]

I switched to a different environment (with Bazel 1.1.0) and with @armooo 's suggested WORKSPACE it now emits a different error:

ERROR: .../dbx_build_tools/build_tools/bzl_lib/itest/BUILD:27:1: in dbx_sh_binary rule @dbx_build_tools//build_tools/bzl_lib/itest:bzl-itest-init:
Traceback (most recent call last):
	File ".../dbx_build_tools/build_tools/bzl_lib/itest/BUILD", line 27
		dbx_sh_binary(name = 'bzl-itest-init')
	File ".../dbx_build_tools/build_tools/sh/sh.bzl", line 9, in dbx_sh_binary_impl
		write_runfiles_tmpl(ctx, <2 more arguments>)
	File ".../dbx_build_tools/build_tools/bazel/runfiles.bzl", line 50, in write_runfiles_tmpl
		is_windows(ctx)
	File ".../dbx_build_tools/build_tools/windows/windows.bzl", line 2, in is_windows
		ctx.target_platform_has_constraint(<1 more arguments>)
	File ".../dbx_build_tools/build_tools/windows/windows.bzl", line 2, in ctx.target_platform_has_constraint
		platform_common.ConstraintValueInfo
object of type 'platform_common' has no field 'ConstraintValueInfo'
ERROR: Analysis of target '@dbx_build_tools//build_tools:bzl' failed; build aborted: Analysis of target '@dbx_build_tools//build_tools/bzl_lib/itest:bzl-itest-init' failed; build aborted

For last week's experiment I was basically trying with a fresh Bazel (3.5.1) installation from brew. Not sure what other Bazel options you might need to debug this issue.

[benjaminp]

1.1.0 is really old and definitely will not work.

[fcorange]

(Edit: same setup worked fine on ubuntu. Seems to be a mac env related issue.)

Did a bit digging into this issue.

Environment:
OS: Mac OS Catalina 10.15.5
Bazel version 3.1.0
.bazelrc and WORKSPACE from current README.md @ HEAD (3245b6f)

Error occurred when trying to build bzl (bazel build @dbx_build_tools//build_tools:bzl):

ERROR: While resolving toolchains for target @dbx_build_tools//build_tools/py:check_conflicts: No matching toolchains found for types @bazel_tools//tools/cpp:toolchain_type. Maybe --incompatible_use_cc_configure_from_rules_cc has been flipped and there is no default C++ toolchain added in the WORKSPACE file? See https://github.com/bazelbuild/bazel/issues/10134 for details and migration instructions.

Adding --toolchain_resolution_debug to the build command gives more details:

INFO: ToolchainResolution:     Toolchain constraint @platforms//os:os has value @platforms//os:ios, which does not match value @platforms//os:linux from the target platform @dbx_build_tools//build_tools/cc:linux-x64-drte-off
INFO: ToolchainResolution:   Rejected toolchain @local_config_cc//:cc-compiler-watchos_x86_64, because of target platform mismatch
INFO: ToolchainResolution:   No toolchains found

It seems that the error has something to do with execution platform. I commented out build --host_platform @dbx_build_tools//build_tools/cc:linux-x64-drte-off line in .bazelrc file and this time it gave a different error:

ERROR: .../dbx_build_tools/build_tools/BUILD:68:1: in dbx_py_binary rule @dbx_build_tools//build_tools:bzl:
Traceback (most recent call last):
	File ".../dbx_build_tools/build_tools/BUILD", line 68
		dbx_py_binary(name = 'bzl')
	File ".../dbx_build_tools/build_tools/py/py.bzl", line 610, in _dbx_py_binary_impl
		dbx_py_binary_base_impl(ctx, <1 more arguments>)
	File ".../dbx_build_tools/build_tools/py/py.bzl", line 659, in dbx_py_binary_base_impl
		emit_py_binary(ctx, main = main, <10 more arguments>)
	File ".../dbx_build_tools/build_tools/py/common.bzl", line 416, in emit_py_binary
		conflict_args.add_all(<2 more arguments>)
map_each must be a function that accepts a single positional argument

[benjaminp]

I should have mentioned earlier that various things like our CPython are Linux-specific today. So, even if this immediate toolchain problem is overcome, there will be more failures.

[fcorange]

Thanks, yes I've since switched to a Ubuntu image running in a containerized env and it works fine now.

I did run into an issue though with latest master head, I've attached details in #11.