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regression: temporary value dropped while borrowed #113237

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regression: temporary value dropped while borrowed#113237
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T-compilerRelevant to the compiler team, which will review and decide on the PR/issue.regression-from-stable-to-stablePerformance or correctness regression from one stable version to another.
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1.71.0

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@Mark-Simulacrum
Mark-Simulacrum
opened on Jul 1, 2023

https://crater-reports.s3.amazonaws.com/beta-1.71-4/beta-2023-06-25/reg/munge-0.3.0/log.txt

[INFO] [stdout] error[E0716]: temporary value dropped while borrowed
[INFO] [stdout]    --> src/lib.rs:194:18
[INFO] [stdout]     |
[INFO] [stdout] 194 |         a = &mut MaybeUninit::uninit();
[INFO] [stdout]     |                  ^^^^^^^^^^^^^^^^^^^^^- temporary value is freed at the end of this statement
[INFO] [stdout]     |                  |
[INFO] [stdout]     |                  creates a temporary value which is freed while still in use
[INFO] [stdout] 195 |         b = &mut MaybeUninit::uninit();
[INFO] [stdout] 196 |         let _ = a;
[INFO] [stdout]     |                 - borrow later used here
[INFO] [stdout]     |
[INFO] [stdout] help: consider using a `let` binding to create a longer lived value
[INFO] [stdout]     |
[INFO] [stdout] 194 ~         let binding = MaybeUninit::uninit();
[INFO] [stdout] 195 ~         a = &mut binding;
[INFO] [stdout]     |

Activity

  1. Mark-Simulacrum
    added
    T-compilerRelevant to the compiler team, which will review and decide on the PR/issue.
    regression-from-stable-to-betaPerformance or correctness regression from stable to beta.
    on Jul 1, 2023
  2. Mark-Simulacrum
    added this to the 1.71.0 milestone on Jul 1, 2023
  3. rustbot
    added
    I-prioritizeIssue needs a team member to assess the impact. Will be replaced by P-{low,medium,high,critical}
    on Jul 1, 2023

  4. asquared31415 commented on Jul 1, 2023

    @asquared31415
    asquared31415
    on Jul 1, 2023
    Contributor

    edit: whoops there was an FCP for this in #104844 (which is the regressing PR)

    searched nightlies: from nightly-2023-04-17 to nightly-2023-06-06
    regressed nightly: nightly-2023-04-23
    searched commit range: fec9adc...b628260
    regressed commit: 21fab43

  5. hameerabbasi commented on Jul 2, 2023

    @hameerabbasi
    hameerabbasi
    on Jul 2, 2023
    Contributor

    edit: whoops there was an FCP for this in #104844 (which is the regressing PR)

    This particular failure wasn't mentioned in that PR, however. Perhaps it was missed.

  6. Noratrieb commented on Jul 2, 2023

    @Noratrieb
    Noratrieb
    on Jul 2, 2023
    Member

    cc @cjgillot, crater on the PR found no regressions but we got one here. @djkoloski this is your crate^^

  7. lqd commented on Jul 2, 2023

    @lqd
    lqd
    on Jul 2, 2023
    Member

    Interesting, munge-0.3.0 didn't appear as a regression then because it was categorized "broken: missing some deps" by both the before and after toolchains, so #104844 didn't run on it at the time.

  8. djkoloski commented on Jul 2, 2023

    @djkoloski
    djkoloski
    on Jul 2, 2023
    Contributor

    I've fixed the offending tests in tree. It looks like this regression only affected the specific test code, not any functional part of the crate.

  9. apiraino commented on Aug 1, 2023

    @apiraino
    apiraino
    on Aug 1, 2023
    Contributor

    WG-prioritization removing priority (Zulip discussion).

    tbh I'm unsure on the best course of action here: maybe close the issue rather than leave in a undefined state? IIUC I see no clear actionable for us.

    @rustbot label -I-prioritize

  10. rustbot
    removed
    I-prioritizeIssue needs a team member to assess the impact. Will be replaced by P-{low,medium,high,critical}
    on Aug 1, 2023
  11. Mark-Simulacrum
    added
    regression-from-stable-to-stablePerformance or correctness regression from one stable version to another.
    and removed
    regression-from-stable-to-betaPerformance or correctness regression from stable to beta.
    on Aug 18, 2023
  12. rustbot
    added
    I-prioritizeIssue needs a team member to assess the impact. Will be replaced by P-{low,medium,high,critical}
    on Aug 18, 2023

  13. apiraino commented on Aug 21, 2023

    @apiraino
    apiraino
    on Aug 21, 2023
    Contributor

    I think the previous evaluation still stands (again: unless I'm missing some context). @Mark-Simulacrum does it make sense to remove the prioritization? And/or closing the issue?

  14. apiraino
    removed
    I-prioritizeIssue needs a team member to assess the impact. Will be replaced by P-{low,medium,high,critical}
    on Sep 4, 2023

  15. Enselic commented on Nov 2, 2024

    @Enselic
    Enselic
    on Nov 2, 2024
    Member

    maybe close the issue rather than leave in a undefined state? IIUC I see no clear actionable for us.

    No objections for over a year. Let's close.

  16. Enselic
    closed this as completedon Nov 2, 2024
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