Bazel build issue

[DhamodharanG-ai]

I am new to use Bazel universe,

After cloning the repo, I tried to run: bazel build ...:all

But I got the following error:

ERROR: Skipping '...:all': error loading package under directory '': error loading package 'externals/llvm-project/utils/bazel/llvm-project-overlay/mlir/unittests': Every .bzl file must have a corresponding package, but '//mlir:tblgen.bzl' does not have one. Please create a BUILD file in the same or any parent directory. Note that this BUILD file does not need to do anything except exist.

[j2kun]

I think the most recent push of the PDLL article might have landed the tutorial at a bad upstream LLVM commit hash. I cannot reproduce this myself but I see a different, perhaps related issue. I will try bumping it to a more recent commit and see if that resolves the issue.

In the meantime, if you're working on a specific tutorial, you could check out the commit for that tutorial instead. E.g., checkout 031e5fe for the verifiers tutorial

[j2kun]

ah I see the problem. The CMake build added the externals directory, which is conflicting with the glob in bazel build ...:all because the external LLVM from that directory includes bazel files.

You can get around this by just building a specific target, either bazel build //tools:tutorial-opt for the main binary, or else bazel test //tests/...:all for tests.

I will try to find a better fix.

[j2kun]

I found a slightly better fix: adding --deleted_packages=externals to .bazelrc. Try updating to the latest commit of this repository and running bazel build ...:all again.