Delete nonreduced fuzz inputs #239

1. 
   maflcko commented at 2:28 pm on September 7, 2025: contributor

   As per the usual process to avoid wasted CI resources and timeouts when CI runs on large and presumed irrelevant inputs.

   Normally, deletion of non-reduced fuzz inputs should happen after feature-freeze on the master Bitcoin Core branch, but before branch-off, so that the latest release branch retains mostly valid fuzz inputs.

   Previous: #221

   To “reproduce”

   Install a fresh VM, as explained in the bash script’s doc, and run it:

   0apt update && apt install curl -y
   1curl -L -O https://raw.githubusercontent.com/bitcoin-core/bitcoin-maintainer-tools/main/delete_nonreduced_fuzz_inputs.sh
   2bash delete_nonreduced_fuzz_inputs.sh
   

   To “test”

   • Keep an eye on coverage stats, to ensure it doesn’t drop
   • Re-run the script, to ensure it is “reproducible” to some extent
   • Anything else you think is important to test or review

   CI

   CI should pass, except for a lint failure, which should light up on any changes like this pull request, which delete fuzz inputs.

2. Delete fuzz inputs b076b4b6ca
3. Reduced inputs for afl-cmin e4d6ddc1be
4. Reduced inputs for fuzzer 32920ab405
5. Reduced inputs for fuzzer,address,undefined,integer a1a5f2c539
6. 
   maflcko commented at 3:34 pm on September 7, 2025: contributor

   Storage device usage (du -sh ./fuzz_corpora/)

   6.2G -> 2.9G

   Determinism

   • ~145k fuzz input files deleted

   0git diff origin/main a1a5f2c539622e19185563c8a161bc46106ab66a --stat | tail -1
   1 145882 files changed, 479508 deletions(-)
   

   • Cross-diff with a second run of the script: 13k fuzz input files

   0git -c diff.renameLimit=8007 diff --stat HEAD a1a5f2c539622e19185563c8a161bc46106ab66a | tail -1 
   1 13428 files changed, 1835 insertions(+), 1785 deletions(-)
   

   Coverage

   main: https://drahtbot.space/host_reports/DrahtBot/reports/coverage_fuzz/monotree/7e58c94112d061af/8896c4758d4fd066/fuzz.coverage/index.html

   this pull: https://drahtbot.space/host_reports/DrahtBot/reports/coverage_fuzz/monotree/7e58c94112d061af/a1a5f2c539622e19/fuzz.coverage/index.html

7. 
   dergoegge commented at 1:04 pm on September 8, 2025: member

   ACK a1a5f2c539622e19185563c8a161bc46106ab66a

   Ran the script myself and got the ~same size reduction

8. dergoegge merged this on Sep 8, 2025
9. dergoegge closed this on Sep 8, 2025

   ---

10. 
    marcofleon commented at 3:16 pm on September 8, 2025: contributor

    original coverage: https://marcofleon.github.io/coverage/original_fuzz_corpora/ reduced coverage: https://marcofleon.github.io/coverage/reduced_fuzz_corpora/

Contributors
maflcko dergoegge marcofleon