Also keep fuzz inputs that increase coverage on older branches #266

1. 
   ekzyis commented at 2:49 pm on March 22, 2026: none

   closes #265

   I think this does what was suggested in #265 (comment).

   I haven’t run this yet. I only ran the original script once in a ubuntu 24.04 vm.

   I’m currently concerned with two things:

   1. Can I continue to set the output dir of the fuzz engines to the real corpus, given hash-based filenames for the fuzz inputs, so overwrites would be idempotent? Before, afl-cmin was only run once per fuzz target. libFuzzer via the test runner was run once per sanitizer.

   2. I’m new to fuzzing. Did I actually understand what I’m doing here?

2. ekzyis marked this as a draft on Mar 22, 2026
3. Also keep fuzz inputs that increase coverage on older branches 888f0bb249
4. ekzyis force-pushed on Mar 22, 2026
5. in delete_nonreduced_fuzz_inputs.sh:106 in 888f0bb249 outdated

   114-      git commit -m "Reduced inputs for ${sanitizer}"
   115-    )
   116+      (
   117+        cd ../qa-assets
   118+        git add "${FUZZ_CORPORA_DIR}"
   119+        git commit -m "Reduced inputs for ${sanitizer}"
   

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   ekzyis commented at 2:53 pm on March 22, 2026:

   This is going to create a commit per sanitizer and ref. I think it should create one commit per sanitizer for all refs (without wasting time rebuilding the same ref multiple times), or at least mention the ref in the commit message.
6. in delete_nonreduced_fuzz_inputs.sh:44 in 888f0bb249 outdated

   38@@ -39,29 +39,45 @@ git clone --depth=1 https://github.com/bitcoin-core/qa-assets.git
   39   git commit -a -m "Delete fuzz inputs"
   40 )
   41 
   42-git clone --depth=1 https://github.com/bitcoin/bitcoin.git
   43+# TODO: optimize? --no-single-branch increased size from 69M to 170M
   44+# could use ls-remote to list tags and then only fetch tags we need
   45+git clone --depth=1 --no-single-branch https://github.com/bitcoin/bitcoin.git
   

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   ekzyis commented at 2:56 pm on March 22, 2026:

   not sure how resource-constrained the vms are on which this will run
7. Fix array syntax issue 8486b0f98a
8. Skip versions before 29.x because of cmake 129b9f6a7d
9. Fix afl-cmin directory already exists error b52604091e
10. Fix mv same file error 78f513dab4

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