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Comment by afandian | Hacker News Reader

Can someone with familiarity with Bazel give any clues how to build? `bazel build` does something, but I end up with `bazel-build` and `bazel-build` with no obvious build artefacts.

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In bazel //... is the equivalent of the 'all' target in make:

    bazel build //...
    bazel test //...
    bazel query //...

The last one should list all targets (from what I remember).

Thanks! That last one lists 84 results. None looks obviously like 'main'. Trying a random one:

    bazel run //in_memory/clustering:graph
    ERROR: Cannot run target //in_memory/clustering:graph

I'm going to wait until someone updates the readme I think!

considering the repo doesn't contain a cc_binary build rule, I'm inclined to believe there's no demo, the easiest way to get started (if you want to play around from scratch) would be to add a cc_binary, point that to a main.cpp file which depends on the library targets you want, e.g "//in_memory/clustering:graph" and ensure there's sufficient visibility from the targets.

Then most likely this is meant to be used primarily as a library. You should wait until they open source the tests (soon, per another commenter). Those will be runnable targets.

`bazel run` is for a rule that has been marked `executable = True` and there is no such rule in the repository.

If you `bazel build //...`, you should get the compiled libs under `bazel-out/*fastbuild/bin/`.

Just to follow up on the above replies, you could also just build a single package. For example, you could build asynchronous_union_find with `bazel build //in_memory/connected_components:asynchronous_union_find`. (This isn't very useful outside of the context of a cc_binary rule.)

This in turn allows you to only build and use the 'package' you care about without having to build the whole repo in other projects. Continuing on the above example, if you only wanted to use the asynchronous_union_find.h header file in your project, somewhere in your WORKSPACE file, you add the graph-mining library using a git_repository rule (see WORKSPACE.bazel for examples), and in a cc_library rule in a BUILD file inside your project, you can add a `@graph-mining//in_memory/connected_components:asynchronous_union_find`. Then you can include it as a header elsewhere. Building your project then only builds that package and its dependencies, and not the entire graph-mining library.

Interesting. I always had in back of my mind this notion that I ought to check bazel one of these days. So, one of these days is then today. In order to install bazel, recommended way seems to be to install bazelisk first and just rename that to bazel and move it somewhere on the path like /usr/local/bin/bazel.. fine. Now when I run query it warned me about JDK.. huh. Now when I run build it errored and failed due to missing JAVA with "WARNING: Ignoring JAVA_HOME, because it must point to a JDK, not a JRE.". Ok, I'm not using Java - let's check which Java JDK/JRE to use these days and after few minutes of googling I'm not up for it anymore and that, ladies and gentlemen, is where this day is then up for another day after all. Pathetic how cargo and even npm/yarm spoiled us.

edit: thanks to https://sdkman.io/ it's up and running. It wasn't _that_ bad after all.

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