bug#20145: (guix build download) leaks file descriptor on TLS connections

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

Back in 2015, I closed <https://issues.guix.gnu.org/issue/20145> saying:

> ludo@gnu.org (Ludovic Courtès) skribis:
>
>> When opening an HTTPS connection, the file descriptor beneath the port
>> returned by ‘tls-wrap’ is leaked.
>>
>> This is not a problem in most cases (downloads) because the process is
>> left as soon as the download is over.
>>
>> This is more problematic for ‘guix lint’, which may open a large number
>> of HTTPS connections for the ‘source’ and ‘home-page’ checkers when
>> working on all the packages.
>
> This is essentially solved by commits
> 14d6ca3e4dd23ee92adb5e2fcf58546e67534631 and
> 097a951e96718a037dbfa6d579e2d26f7dab3e82.
>
> One still needs to be careful, though, for instance because closing a
> chunked encoding port (which is a custom binary input port wrapped
> around the real socket port) still fails to close the raw socket port
> that’s behind the TLS session record port.

Unfortunately, the bug just reported by Valentin and by Ricardo are
instances of this problem (at least I checked with crates.io and it
uses chunked encoding, leading to a file descriptor leak):

  https://issues.guix.gnu.org/issue/38857
  https://issues.guix.gnu.org/issue/38836

To be continued…

Ludo’.