Re: branch master updated: remote-server: Fix fetch worker crash.

Re: branch master updated: remote-server: Fix fetch worker crash.

[Ludovic Courtès]

Hi,

m.othacehe@gmail.com (Mathieu Othacehe) skribis:

> --- a/src/cuirass/scripts/remote-server.scm
> +++ b/src/cuirass/scripts/remote-server.scm
> @@ -376,7 +376,10 @@ directory."
>              (when (> duration 60)
>                (log-message "fetching '~a' took ~a seconds."
>                             drv duration)))))
> -       (register-gc-roots drv)
> +       ;; The derivation may have been GC'ed by that time. Do not try to
> +       ;; register its outputs in that case.
> +       (when (file-exists? drv)
> +         (register-gc-roots drv))

I think it’s be safer (less prone to TOCTTOU races) to write it as:

  (catch 'system-error
    (lambda ()
      (register-gc-roots drv))
    (lambda args
      (unless (= ENOENT (system-error-errno args)) ;collected in the meantime
        (apply throw args))))

Ludo’.

Re: branch master updated: remote-server: Fix fetch worker crash.

[Mathieu Othacehe]

Hey Ludo,

> I think it’s be safer (less prone to TOCTTOU races) to write it as:
>
>   (catch 'system-error
>     (lambda ()
>       (register-gc-roots drv))
>     (lambda args
>       (unless (= ENOENT (system-error-errno args)) ;collected in the meantime
>         (apply throw args))))

Oh, indeed! Fixed with 6dcf2f65cea920b9b1c265de3e2b0abe0048a08e.

Thanks,

Mathieu