dotnet/roslyn

EE: Cannot reference duplicate typename with no alias

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#1,530 opened on Mar 24, 2015

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 (0 comments) (0 reactions) (0 assignees)C# (20,414 stars) (4,257 forks)batch import
Area-InteractiveBugInteractive-Debugginghelp wanted

Description

Ported from TFS WorkItem: 1144921

  1. Created By Chuck Stoner (3/24/2015 10:42:17 AM)
  1. Edited By Manish Jayaswal (3/24/2015 11:08:07 AM)

this is not a regression from Dev12.

Contributor guide

Tech stack
csharp
Domain
tooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
5
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
understanding of C# extern aliasbasic knowledge of Roslyn compiler
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
15
Research direction
The issue describes a bug where 'EE: Cannot reference duplicate typename with no alias' in the Roslyn compiler. To reproduce, follow the steps: create two identical libraries (a1.dll and a2.dll), compile with extern alias, and debug. The expected behavior is that evaluating 'new A()' works, but it fails. Since the issue is from 2015 and unassigned, first verify if the bug still exists in the current Roslyn version. Look at related code in the EE (Expression Evaluator) module, possibly in files like 'src/ExpressionEvaluator/CSharp/...' or 'src/ExpressionEvaluator/VisualBasic/...'. Check for any linked PRs or comments that might provide clues. If confirmed, the fix likely involves handling duplicate types with aliases in the expression evaluator.