Bitcoin Core: Test The Test

The goal of these exercises is to learn the Bitcoin Core development environment through the Bitcoin Test Framework.

Set Up

1. Clone the Bitcoin Core repository
2. Checkout the 26.0 tag (commit 44d8b13c81e5276eb610c99f227a4d090cc532f6)
3. Build Bitcoin Core
   • The docs in the repo should provide sufficient guidance for this
   • If you have any problems, search the issues on GitHub or try Bitcoin Stack Exchange
   • Recommended minimal configure options:
     • ./configure --disable-bench --disable-fuzz-binary --enable-debug --without-gui --enable-suppress-external-warnings
4. Run all the functional tests
   • All tests should pass!

Challenge

1. Choose a target test from https://github.com/bitcoin/bitcoin/tree/44d8b13c81e5276eb610c99f227a4d090cc532f6/test/functional
2. Write a minimal commit that makes this one single test fail, and no others!
3. Submit your commit as a diff using git show <commit hash>

Example

Target test: test/functional/feature_abortnode.py

Commit:

commit 47e782ade192846393786881c3c5f30c080d21ff
Author: Matthew Zipkin <[email protected]>
Date:   Wed Nov 29 10:32:16 2023 -0500

    make feature_abortnode.py fail

diff --git a/src/validation.cpp b/src/validation.cpp
index 1fd8f0e326..8b6494a1d7 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -3000,7 +3000,7 @@ bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex*
             // If we're unable to disconnect a block during normal operation,
             // then that is a failure of our local system -- we should abort
             // rather than stay on a less work chain.
-            AbortNode(state, "Failed to disconnect block; see debug.log for details");
+            // AbortNode(state, "Failed to disconnect block; see debug.log for details");
             return false;
         }
         fBlocksDisconnected = true;