Help users move the colon in their label

[alexeagle]

In Angular, I have a lot of users being confused about how to formulate a label that addresses their file.

For example, we install stuff from npm, and the user wants to reference
node_modules/@package/name/path/to/file.json
They used a rule to install the dependencies which creates a workspace called npm.

How does the developer know which of these labels to use?

• @npm//node_modules/@package/name/path/to:file.json (this is the intuitive one since slashes after the colon are unusual)
• @npm//:node_modules/@package/name/path/to/file.json (might look right to them since their package.json was in the root of their WORKSPACE and they already typed this once)

Of course the answer is to look around for the nearest ancestor BUILD.bazel file in the tree, but that requires they know how to look in $(bazel info output_base)/external/npm/... to locate files.

The error from bazel is target not declared in package or no such package depending where the wrong colon is, and also maybe add exports_files which is not helpful in an external BUILD file.

The right error message would be you probably meant to put the colon here: @npm//node_modules/@package/name:path/to/file.json

[Jonathan34]

Of course the answer is to look around for the nearest ancestor BUILD.bazel file in the tree, but that requires they know how to look in $(bazel info output_base)/external/npm/... to locate files.

that is actually a must to understand what s going on and fix the deps and import path. Thank you for that!

[jin]

Related: #9364

[sgowroji]

Hi there! We're doing a clean up of old issues and will be closing this one. Please reopen if you’d like to discuss anything further. We’ll respond as soon as we have the bandwidth/resources to do so.