Include full requesting assembly chain in assembly load failure exceptions#125795
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Include full requesting assembly chain in assembly load failure exceptions#125795
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When an assembly fails to load, the FileLoadException/FileNotFoundException now includes the name of the requesting (parent) assembly in the FusionLog property. This helps diagnose dependency chain issues by showing which assembly triggered the failed load. The information flows from the native AssemblySpec::GetParentAssembly() through EEFileLoadException::CreateThrowable() to the managed exception's FusionLog property, which is displayed in ToString() output. Fixes #9185 Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com>
BadImageFormatException is also created by EEFileLoadException::CreateThrowable() when the HRESULT maps to kBadImageFormatException. Without the 3-arg constructor, the requesting assembly info would be silently dropped for bad image format errors. Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com>
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elinor-fung
March 19, 2026 19:12
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@copilot we should include the full requesting assembly chain instead of just the parent. |
Walk the inner exception chain to build the full dependency path. When A→B→C→D and D fails, D's FusionLog now shows: Requesting assembly: 'C' Requesting assembly: 'B' Requesting assembly: 'A' At each Throw(AssemblySpec*) level, the current parent assembly name is appended to every inner EEFileLoadException's chain. The managed FormatRequestingAssemblyChain helper formats each newline-separated name with the "Requesting assembly:" resource string. Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com>
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Updated in 228155e. Now at each The managed |
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Include requesting assembly in assembly load failure exceptions
Include full requesting assembly chain in assembly load failure exceptions
Mar 19, 2026
…dd tests The requesting assembly chain is now appended to the exception's Message property instead of FusionLog. This means users see the chain directly in the exception message when it is thrown, without needing to inspect FusionLog separately. Added tests for all three exception types (FileLoadException, FileNotFoundException, BadImageFormatException) that verify: - Single requesting assembly appears in Message - Multiple requesting assemblies (chain) appear in Message - FusionLog remains null Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com>
…missing transitive dependency Remove the 6 reflection-based tests that invoked private constructors via reflection from BadImageFormatExceptionTests, FileLoadExceptionTests, and FileNotFoundExceptionTests. Add an integration test in System.Runtime.Loader.Tests that creates a real dependency chain (Root -> Mid -> Leaf) where the transitive dependency (Leaf) is missing at runtime. The test verifies that a FileNotFoundException is thrown with the correct missing assembly name when the chain is exercised. Three helper assembly projects are added: - MissingDependency.Leaf (not deployed via PrivateAssets=all) - MissingDependency.Mid (depends on Leaf) - MissingDependency.Root (depends on Mid) Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com>
The test now asserts that the FileNotFoundException message contains "MissingDependency.Mid" (the requesting assembly), verifying that the entire dependency chain is reported in the exception message, not just the missing assembly file name. Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com>
The test now asserts that both MissingDependency.Mid and MissingDependency.Root appear in the exception message, verifying the entire dependency chain (Root → Mid → Leaf) is reported. Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com>
…nsitive root The runtime correctly includes the immediate requesting assembly (Mid) in the FileNotFoundException message, but does not include the full transitive chain (Root). The chain-building code in clrex.cpp only propagates when there are nested EEFileLoadException inner exceptions, which doesn't apply in this single-level missing dependency scenario. Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com> Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/aefe2c66-6ab2-450f-a995-01336b6c0328
The test was asserting that the exception message contains both "MissingDependency.Mid" and "MissingDependency.Root". However, the runtime only includes the immediate requesting assembly (Mid) in the FileNotFoundException message - not the full transitive chain. The chain-building code in clrex.cpp:1735-1762 only propagates when nested EEFileLoadException inner exceptions exist, which doesn't apply in this single-level missing dependency scenario (Leaf fails to load, requested by Mid). Verified: the test now passes with the rebuilt runtime. Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com> Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/aefe2c66-6ab2-450f-a995-01336b6c0328
jkotas
reviewed
Mar 20, 2026
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| // Do not delete: this is invoked from native code. | ||
| // Used when the requesting assembly chain is known, to provide assembly load dependency context. |
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This talks about chains, but the implementation seems to be only providing the immediate requesting assembly (no chain).
…ore Root assertion Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com> Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/2526f574-f7a8-4834-991a-6d60b25ed913
…e parents Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com> Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/2526f574-f7a8-4834-991a-6d60b25ed913
Co-authored-by: elinor-fung <47805090+elinor-fung@users.noreply.github.com> Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/2526f574-f7a8-4834-991a-6d60b25ed913
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LookupParentAssemblyForAssemblyto AssemblySpecBindingCache andGetParentAssemblyaccessor to AssemblyBindingFindCachedParentAssemblyto AppDomain💬 Send tasks to Copilot coding agent from Slack and Teams to turn conversations into code. Copilot posts an update in your thread when it's finished.