fuzz: Remove unused TimeoutExpired catch in fuzz runner #32388

1. 
   maflcko commented at 5:57 pm on April 30, 2025: member

   Currently, the way to check for libFuzzer is to search the stderr of the fuzz executable when passed -help=1 for the string libFuzzer. See also https://github.com/bitcoin/bitcoin/blob/14b8dfb2bd5e2ca2b7c0c9a7f7d50e1e60adf75c/contrib/devtools/deterministic-fuzz-coverage/src/main.rs#L90-L101

   The python test runner additionally includes a timeout catch, which was needed before the plain read_file fallback was implemented, see https://github.com/bitcoin/bitcoin/blob/14b8dfb2bd5e2ca2b7c0c9a7f7d50e1e60adf75c/src/test/fuzz/fuzz.cpp#L251.

   However, it is no longer needed and the printed error message would be wrong, so remove it.

   (side-note: On Windows the fuzz executable seems to time out when an assert is hit in a debug build, see #32341 (comment). However, no one is running fuzz debug on Windows. Also, the newly added debug logging is a preferable replacement in this case anyway.)

2. fuzz: Remove unused TimeoutExpired catch in fuzz runner

   Can be reviewed with --ignore-all-space

   fa4804009c
3. 
   DrahtBot commented at 5:57 pm on April 30, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32388.

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4. DrahtBot added the label Tests on Apr 30, 2025
5. fanquake requested review from dergoegge on May 1, 2025
6. fanquake requested review from marcofleon on May 1, 2025
7. 
   marcofleon commented at 4:36 pm on May 2, 2025: contributor

   crACK fa4804009ceba96926edd7f55ea22442ebdc665d
8. 
   kevkevinpal commented at 11:50 pm on May 5, 2025: contributor

   crACK fa48040

   Agreed the error message would be wrong but also not needed anymore

9. brunoerg approved
10. 
    brunoerg commented at 10:23 pm on May 6, 2025: contributor

    code review ACK fa4804009ceba96926edd7f55ea22442ebdc665d
11. 
    Crypt-iQ commented at 10:45 am on May 7, 2025: contributor

    crACK fa4804009ceba96926edd7f55ea22442ebdc665d

    Just curious, why did adding the read_file fallback cause the timeout to be unused? I can’t really speak to the Windows side-effect as I don’t totally understand it.

12. fanquake merged this on May 7, 2025
13. fanquake closed this on May 7, 2025

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14. 
    maflcko commented at 11:36 am on May 7, 2025: member

    Just curious, why did adding the read_file fallback cause the timeout to be unused?

    read_file was implemented in https://github.com/bitcoin/bitcoin/commit/f59bee3fb242c9e02781a35272cf9644f37e7fc1. Previously, it would just call read_stdin, which then may time out (because nothing is fed into stdin).

15. maflcko deleted the branch on May 7, 2025

Contributors
maflcko DrahtBot marcofleon kevkevinpal brunoerg Crypt-iQ

Review Requested
dergoegge

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