`@` and `@workspacename` considered different repositories

Description of the problem / feature request / question:

Bazel evaluates the same Skylark file multiple times if it is loaded with a local path and an absolute path. This creates problems for rules, since everything gets defined twice. It is particularly problematic for named providers, since the duplicate definitions are neither equivalent nor compatible.

We ran into this issue when trying to migrate rules_go to use named providers. We load our .bzl files with local labels in our own repository, but repositories that depend on ours load using absolute labels, which causes errors.

Bazel should not evaluate the same .bzl file in the same repository more than once.

If possible, provide a minimal example to reproduce the problem:

Create an empty workspace with these files.

# WORKSPACE
workspace(name = "scratch")

# BUILD
load("//:def.bzl", "a")
load("@scratch//:def.bzl", "a")

# def.bzl
print("def.bzl evaluated")
a = 10

Run bazel query //... to evaluate the files. The message is printed twice.

$ bazel query //...
____Loading package: 
WARNING: /usr/local/google/home/jayconrod/Code/scratch/def.bzl:1:1: def.bzl evaluated.
WARNING: /usr/local/google/home/jayconrod/.cache/bazel/_bazel_jayconrod/1df8d8ad4cb35ee83522d81953b4d69f/external/scratch/def.bzl:1:1: def.bzl evaluated.
____Empty results

Environment info

• Operating System: Linux
• Bazel version (output of bazel info release): 0.5.0

cc @ianthehat

[dkelmer]

This issue should now be fixed at head. Please reopen the bug if it doesn’t address your use case. Note that referencing @<workspace_name> from the command line will still be treated as a separate repository.

[ittaiz]

Didn’t know that. Will do, thanks.