Fix callTracer missing revertReason and nested calls for reverted transactions#9651
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usmansaleem merged 6 commits intobesu-eth:mainfrom Jan 22, 2026
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This commit fixes two related issues where Besu's callTracer was not
decoding and populating the revertReason field when transactions reverted
with a message, making output incompatible with Geth.
Issues fixed:
1. Root-level calls that reverted were setting output but not revertReason
2. Nested calls that reverted were not decoding revertReason from output
Changes:
- CallTracerErrorHandler.handleRootError(): Added revertReason decoding
for non-creation calls that revert
- CallTracerErrorHandler.setOutputAndErrorStatus(): Added revertReason
decoding from output data when REVERT opcode is executed
The fix uses the existing JsonRpcErrorResponse.decodeRevertReason() method
via CallTracerResult.Builder.revertReason() to decode ABI-encoded Error(string)
data from the output field.
Before fix:
{
"output": "0x08c379a0...",
"error": "execution reverted"
}
After fix:
{
"output": "0x08c379a0...",
"error": "execution reverted",
"revertReason": "This function always reverts"
}
Signed-off-by: Usman Saleem <usman@usmans.info>
Process trace frames for reverted transactions to capture nested calls that
occurred before the revert. Previously, Besu skipped frame processing for
all unsuccessful transactions, causing nested calls to be completely omitted.
The fix distinguishes between:
- Transactions that reverted (REVERT opcode): Process frames to capture calls
- Transactions with exceptional halt (stack underflow, etc.): Skip frames
This matches Geth behavior where the full execution history is captured
even when the transaction ultimately reverts.
Before fix:
{
"error": "execution reverted",
"revertReason": "...",
// Missing calls array
}
After fix:
{
"error": "execution reverted",
"revertReason": "...",
"calls": [
{
"type": "STATICCALL",
"error": "execution reverted",
"revertReason": "..."
}
]
}
Signed-off-by: Usman Saleem <usman@usmans.info>
Gabriel-Trintinalia
approved these changes
Jan 21, 2026
…rt-issues Signed-off-by: Usman Saleem <usman@usmans.info>
…rt-issues Signed-off-by: Usman Saleem <usman@usmans.info>
…rt-issues Signed-off-by: Usman Saleem <usman@usmans.info>
macfarla
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Feb 6, 2026
…nsactions (besu-eth#9651) * Fix callTracer missing revertReason field for reverted transactions This commit fixes two related issues where Besu's callTracer was not decoding and populating the revertReason field when transactions reverted with a message, making output incompatible with Geth. Issues fixed: 1. Root-level calls that reverted were setting output but not revertReason 2. Nested calls that reverted were not decoding revertReason from output Changes: - CallTracerErrorHandler.handleRootError(): Added revertReason decoding for non-creation calls that revert - CallTracerErrorHandler.setOutputAndErrorStatus(): Added revertReason decoding from output data when REVERT opcode is executed The fix uses the existing JsonRpcErrorResponse.decodeRevertReason() method via CallTracerResult.Builder.revertReason() to decode ABI-encoded Error(string) data from the output field. Before fix: { "output": "0x08c379a0...", "error": "execution reverted" } After fix: { "output": "0x08c379a0...", "error": "execution reverted", "revertReason": "This function always reverts" } * Fix callTracer missing nested calls when transaction reverts Process trace frames for reverted transactions to capture nested calls that occurred before the revert. Previously, Besu skipped frame processing for all unsuccessful transactions, causing nested calls to be completely omitted. The fix distinguishes between: - Transactions that reverted (REVERT opcode): Process frames to capture calls - Transactions with exceptional halt (stack underflow, etc.): Skip frames This matches Geth behavior where the full execution history is captured even when the transaction ultimately reverts. Before fix: { "error": "execution reverted", "revertReason": "...", // Missing calls array } After fix: { "error": "execution reverted", "revertReason": "...", "calls": [ { "type": "STATICCALL", "error": "execution reverted", "revertReason": "..." } ] } --------- Signed-off-by: Usman Saleem <usman@usmans.info>
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PR description
This PR fixes two critical issues in Besu's
callTracerimplementation that caused incompatibility with Geth when tracing reverted transactions.Issue 1: Missing
revertReasonfield for reverted transactionsProblem:
When a transaction reverted with an Error(string) message, Besu's callTracer output included the ABI-encoded revert data in the
outputfield but wasmissing the decoded
revertReasonfield that Geth provides.Root Cause:
CallTracerErrorHandlerwas not decoding revert reasons from the output data.Fix:
revertReasonDecoded(String)method toCallTracerResult.Builderfor setting revertReason without hex fallbackCallTracerErrorHandler.handleRootError()andCallTracerErrorHandler.setOutputAndErrorStatus()to useJsonRpcErrorResponse.decodeRevertReason()revertReasonfield when the revert data is a valid Error(string) format (starts with 0x08c379a0), ensuring Geth compatibilityFiles Changed:
CallTracerResult.java- AddedrevertReasonDecoded()methodCallTracerErrorHandler.java- Added revert reason decoding logicIssue 2: Missing nested
callsarray when transaction revertsProblem:
When a transaction reverted, Besu's callTracer was not capturing nested calls at all. The
callsarray was completely missing from the output, eventhough Geth includes all nested calls up to the point of revert.
Root Cause:
CallTracerResultConverter.buildCallHierarchyFromFrames()had an early return that prevented frame processing for ALL unsuccessful transactions,including reverts.
Fix:
callsarrayFiles Changed:
CallTracerResultConverter.java- Updated condition inbuildCallHierarchyFromFrames()Fixed Issue(s)
Thanks for sending a pull request! Have you done the following?
doc-change-requiredlabel to this PR if updates are required.Locally, you can run these tests to catch failures early:
./gradlew spotlessApply./gradlew build./gradlew acceptanceTest./gradlew integrationTest./gradlew ethereum:referenceTests:referenceTests