bazel mod show_repo <canonical repo name> doesn't work for module extension generated repos.

[meteorcloudy]

Description of the bug:

For a module extension generated repo, the following works:

bazel mod show_repo <apparent repo name> --base_module=<module name>

However, it'll be nice to also also have

bazel mod show_repo <canonical repo name>

Which category does this issue belong to?

No response

What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

In the Bazel repo, with Bazel 7.1.0rc2

bazel mod show_repo @@rules_jvm_external~~maven~maven

FATAL: bazel crashed due to an internal error. Printing stack trace:
java.lang.NullPointerException: Cannot invoke "com.google.devtools.build.lib.cmdline.RepositoryName.equals(Object)" because the return value of "com.google.common.collect.ImmutableMap.get(Object)" is null
	at com.google.devtools.build.lib.bazel.bzlmod.modcommand.ModuleArg$CanonicalRepoName.lambda$resolveToRepoNames$1(ModuleArg.java:340)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(Unknown Source)
	at com.google.common.collect.CollectSpliterators$1WithCharacteristics.lambda$tryAdvance$0(CollectSpliterators.java:67)
	at java.base/java.util.stream.Streams$RangeIntSpliterator.tryAdvance(Unknown Source)
	at com.google.common.collect.CollectSpliterators$1WithCharacteristics.tryAdvance(CollectSpliterators.java:67)
	at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(Unknown Source)
	at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(Unknown Source)
	at java.base/java.util.stream.AbstractPipeline.copyInto(Unknown Source)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
	at java.base/java.util.stream.FindOps$FindOp.evaluateSequential(Unknown Source)
	at java.base/java.util.stream.AbstractPipeline.evaluate(Unknown Source)
	at java.base/java.util.stream.ReferencePipeline.findAny(Unknown Source)
	at com.google.devtools.build.lib.bazel.bzlmod.modcommand.ModuleArg$CanonicalRepoName.resolveToRepoNames(ModuleArg.java:341)
	at com.google.devtools.build.lib.bazel.commands.ModCommand.execInternal(ModCommand.java:340)
	at com.google.devtools.build.lib.bazel.commands.ModCommand.exec(ModCommand.java:138)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.execExclusively(BlazeCommandDispatcher.java:664)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.exec(BlazeCommandDispatcher.java:244)
	at com.google.devtools.build.lib.server.GrpcServerImpl.executeCommand(GrpcServerImpl.java:573)
	at com.google.devtools.build.lib.server.GrpcServerImpl.lambda$run$1(GrpcServerImpl.java:644)
	at io.grpc.Context$1.run(Context.java:566)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)

Which operating system are you running Bazel on?

Linux

What is the output of bazel info release?

7.1.0rc2

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse HEAD ?

No response

Is this a regression? If yes, please try to identify the Bazel commit where the bug was introduced.

No response

Have you found anything relevant by searching the web?

No response

Any other information, logs, or outputs that you want to share?

No response

[meteorcloudy]

/cc @Wyverald @SalmaSamy

Relevant code: https://cs.opensource.google/bazel/bazel/+/master:src/main/java/com/google/devtools/build/lib/bazel/bzlmod/modcommand/ModuleArg.java;l=333-343

[Wyverald]

ah, I think this is as simple as removing that if check. if a nonexistent canonical repo name is passed in, we could just let it fail a bit later instead.

[meteorcloudy]

@Wyverald I don't quite understand, I didn't see anywhere in the code that is checking the canonical repo name generated by module extension? (@@rules_jvm_external~~maven~maven does exist, the expected result is to output the repo spec.)

[Wyverald]

I meant removing the check at https://cs.opensource.google/bazel/bazel/+/master:src/main/java/com/google/devtools/build/lib/bazel/bzlmod/modcommand/ModuleArg.java;drc=a54a393d209ab9c8cf5e80b2a0ef092196c17df3;l=339, so we don't check that the canonical repo name is from a module. We can simply not check anything at all and let it fail later if the repo doesn't actually exist.

[fmeum]

@bazel-io fork 7.1.1

[iancha1992]

A fix for this issue has been included in Bazel 7.1.1 RC1. Please test out the release candidate and report any issues as soon as possible.
If you're using Bazelisk, you can point to the latest RC by setting USE_BAZEL_VERSION=7.1.1rc1. Thanks!

[meteorcloudy]

FYI @lberki

[lberki]

Thanks! (any news about reporting something useful when there are modules/repositories that are in error but the one I am interested in is not?)

[meteorcloudy]

I believe a successful resolution result is still a requirement for the bazel mod command? @Wyverald can confirm that.

[lberki]

That's why I think too, although I certainly hoped that that one somehow got fixed in the meantime

[wingsofovnia]

I am still having the issue on 7.1.1:

> bazel --version                                                   
bazel 7.1.1

> bazel mod show_extension @@rules_oci~6.0.5//oci:extensions.bzl%oci
Starting local Bazel server and connecting to it...
 checking cached actions
    Fetching https://bcr.bazel.build/modules/rules_python_gazelle_plugin/0.31.0/source.json
FATAL: bazel crashed due to an internal error. Printing stack trace:
java.lang.NullPointerException: Cannot invoke "com.google.devtools.build.lib.cmdline.RepositoryName.equals(Object)" because the return value of "com.google.common.collect.ImmutableMap.get(Object)" is null
        at com.google.devtools.build.lib.bazel.bzlmod.modcommand.ModuleArg$CanonicalRepoName.lambda$resolveToModuleKeys$0(ModuleArg.java:308)
        at java.base/java.util.stream.ReferencePipeline$2$1.accept(Unknown Source)
        at com.google.common.collect.CollectSpliterators$1WithCharacteristics.lambda$tryAdvance$0(CollectSpliterators.java:67)
        at java.base/java.util.stream.Streams$RangeIntSpliterator.tryAdvance(Unknown Source)
        at com.google.common.collect.CollectSpliterators$1WithCharacteristics.tryAdvance(CollectSpliterators.java:67)
        at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(Unknown Source)
        at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(Unknown Source)
        at java.base/java.util.stream.AbstractPipeline.copyInto(Unknown Source)
        at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
        at java.base/java.util.stream.FindOps$FindOp.evaluateSequential(Unknown Source)
        at java.base/java.util.stream.AbstractPipeline.evaluate(Unknown Source)
        at java.base/java.util.stream.ReferencePipeline.findAny(Unknown Source)
        at com.google.devtools.build.lib.bazel.bzlmod.modcommand.ModuleArg$CanonicalRepoName.resolveToModuleKeys(ModuleArg.java:309)
        at com.google.devtools.build.lib.bazel.bzlmod.modcommand.ExtensionArg.resolveToExtensionId(ExtensionArg.java:66)
        at com.google.devtools.build.lib.bazel.commands.ModCommand.execInternal(ModCommand.java:365)
        at com.google.devtools.build.lib.bazel.commands.ModCommand.exec(ModCommand.java:139)
        at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.execExclusively(BlazeCommandDispatcher.java:664)
        at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.exec(BlazeCommandDispatcher.java:244)
        at com.google.devtools.build.lib.server.GrpcServerImpl.executeCommand(GrpcServerImpl.java:573)
        at com.google.devtools.build.lib.server.GrpcServerImpl.lambda$run$1(GrpcServerImpl.java:644)
        at io.grpc.Context$1.run(Context.java:566)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.base/java.lang.Thread.run(Unknown Source)

[meteorcloudy]

@wingsofovnia Thanks for reporting, we'll fix it.

[meteorcloudy]

@bazel-io fork 7.2.0

[iancha1992]

A fix for this issue has been included in Bazel 7.2.0 RC1. Please test out the release candidate and report any issues as soon as possible.
If you're using Bazelisk, you can point to the latest RC by setting USE_BAZEL_VERSION=7.2.0rc1. Thanks!