Fix crate deps with condition

[ibigbug]

Fixed #1880

[UebelAndre]

Thanks! Is this something you'd be able to add an integration test for at https://github.com/bazelbuild/rules_rust/tree/0.19.1/examples/crate_universe? I thought the alias example there would have caught an issue like this but it's clearly lacking. Could you update this so we don't have aliases break again in the future?

[ibigbug]

sure I'll add it. but sorry for the confusion I think we still need some polish to this PR #1880 (comment)

[ibigbug]

@UebelAndre I think I made some progress, and got a new error

DEBUG: /private/var/tmp/_bazel_yuweiba/f3b87d172301024018ed3e9f856c70fc/external/crate_index/defs.bzl:276:10: {"": {}, "cfg(target_os = \"macos\")": {}}
DEBUG: /private/var/tmp/_bazel_yuweiba/f3b87d172301024018ed3e9f856c70fc/external/crate_index/defs.bzl:276:10: {"": {}}
ERROR: /Users/yuweiba/workspace/projects/clash-rs/clash/BUILD.bazel:4:13: //clash:aarch64-apple-darwin is not a valid select() condition for //clash:lib.
To inspect the select(), run: bazel query --output=build //clash:lib.
For more help, see https://docs.bazel.build/be/functions.html#select.

any suggestions where to go next step?

[ibigbug]

@UebelAndre sorry i wasn't able to make any progress. do you have any suggestions?

[k1nkreet]

For deps since it's a list, it could be done a bit simpler with selects.with_or without for-loop

-        crate_deps += selects.with_or({_CONDITIONS[condition]: deps.values()})
+        crate_deps += selects.with_or({tuple(_CONDITIONS[condition]): deps.values()})

[k1nkreet]

@UebelAndre I think I made some progress, and got a new error

DEBUG: /private/var/tmp/_bazel_yuweiba/f3b87d172301024018ed3e9f856c70fc/external/crate_index/defs.bzl:276:10: {"": {}, "cfg(target_os = \"macos\")": {}}
DEBUG: /private/var/tmp/_bazel_yuweiba/f3b87d172301024018ed3e9f856c70fc/external/crate_index/defs.bzl:276:10: {"": {}}
ERROR: /Users/yuweiba/workspace/projects/clash-rs/clash/BUILD.bazel:4:13: //clash:aarch64-apple-darwin is not a valid select() condition for //clash:lib.
To inspect the select(), run: bazel query --output=build //clash:lib.
For more help, see https://docs.bazel.build/be/functions.html#select.

I've got to the same issue with my small research on this topic. It looks like the problem is module_bzl.j2 defining _CONDITIONS value uses triples from context.conditions holding the values which are not transformed with platforms_template. I'm not really familiar with the tool processing those templates to understand whether it's possible to apply platforms_template to triples inside the template specification. The other option could be to provide additional value in context or change the value of context.conditions according to platforms_template. I wonder if @UebelAndre has any thoughts on that

[UebelAndre]

Hey! So sorry, this one fell off my radar, thanks for the ping.

If you can add a small integration-test/example to this PR I can find some time to context shift to this issue. I think it'd be fine to process more in Rust vs Starlark. The thing I care most about is that issues are easy to identify and to be honest the current implementation fails at that. Simplifying this without changing the interface sounds amazing to me 😄

[k1nkreet]

Since I've spent some time tinkering on cargo-bazel-bin tool to solve the last issue and I've made some progress on it, I took the liberty of opening the new PR where I've added the integration test/example, took the changes from this PR and added fix for this problem