bazelbuild/bazel

Duplicate --config=foo produces a seemingly pointless warning

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#11,592 opened on Jun 15, 2020

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P3help wantedteam-Configurabilityteam-Documentationtype: documentation (cleanup)

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Description

As of Bazel 3.2.0, if you have build --config=foo in multiple places (like .bazelrc and ~/.bazelrc), bazel build produces the following warning:

WARNING: The following configs were expanded more than once: [foo]. For repeatable flags, repeats are counted twice and may lead to unexpected behavior.

It's not clear under which scenario --config=foo may be "repeatable" or produce "unexpected behavior". To my understanding, such a thing cannot happen, and hence the warning seems like a bug. There does not appear to be any conflict in the requested flags. Could the warning be removed?

Contributor guide

Research direction
Identify the location in the Bazel codebase that emits the warning about configs expanded more than once, and analyze whether duplicate config flags can lead to unexpected behavior. If not, propose removing the warning.
Tech stack
java
Domain
build system
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Java
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65