Pack_list_installed?

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1

This morning I was after updating clpBNR to the last release, and started by

 ?- pack_list_installed.
% Contacting server at https://www.swi-prolog.org/pack/query ...

Waiting for Prolog. Close again to force termination ..

The predicate stopped, hitting Ctrl-C didn’t produced any effect.
The message ‘Waiting…’ showed after when I tried to close the console (swipl-win.exe) using the upper right X button.
It’s still there, I must use Windows Task Manager to kill the process…

Edit

The same problem occurs with

?- pack_upgrade(clpBNR).
% Contacting server at https://www.swi-prolog.org/pack/query ..

Edit

Could the cause be that https://ridgeworks.github.io/clpBNR/ causes a 404 on github ? I pinged that url looking for the latest deployment…

2

Seems there is something wrong with your connection to www.swi-prolog.org. As that is on a CDN, the most likely seems some network issue on your site.

If I recall correctly, the contact is written as

setup_call_cleanup(
    http_open(....),
    ...

That is still somewhat problematic as the setup part of setup_call_cleanup/3 is executed using sig_atomic/1 to avoid interrupts leading to a partial initialization and resource leaks.

3

It used to work, and my job is (mainly) on Internet, obviously working… but you’re right that

?- http_open('https://www.swi-prolog.org/',S,[]),stream_info(S),close(S).
Correct to: "http_open:http_open('https://www.swi-prolog.org/',S,[])"? yes

hangs forever, as well… maybe a timeout(60) - just to say - in pack_… functions accessing Internet could be more user friendly.

Well, since I don’t know what I could try to overcome the connection problem, I’ve cloned locally GitHub - ridgeworks/clpBNR: CLP(BNR) module for SWI-Prolog, and will try to upgrade from there.

Thanks

4

Eventually, the low level network stuff should time out. What is more interesting is why this happens? Can your browser connect to www.swi-prolog.org? Could it be a firewall issue that blocks swipl.exe from accessing the network? Could there be a proxy that is not understood? You can try

?- debug(http(_)).
?- http_open('https://www.swi-prolog.org/',S,[]).

and see what it is trying to do.

5

yes, it can.

Don’t know… from long time I switched to my phone hotspot instead of a wired connection, so I’m pretty sure pack_install etc were working some time ago.

Maybe this, because

PS C:\Users\cccar> ping https://www.swi-prolog.org/
Impossibile trovare l'host https://www.swi-prolog.org/. Verificare che il nome sia corretto e riprovare.

Esecuzione di Ping www.google.com [216.58.204.228] con 32 byte di dati:
Risposta da 216.58.204.228: byte=32 durata=61ms TTL=113
Risposta da 216.58.204.228: byte=32 durata=46ms TTL=113
Risposta da 216.58.204.228: byte=32 durata=54ms TTL=113
Risposta da 216.58.204.228: byte=32 durata=62ms TTL=113

Statistiche Ping per 216.58.204.228:
    Pacchetti: Trasmessi = 4, Ricevuti = 4,
    Persi = 0 (0% persi),
Tempo approssimativo percorsi andata/ritorno in millisecondi:
    Minimo = 46ms, Massimo =  62ms, Medio =  55ms

Seems a Windows problem with the DNS … If I run from WSL (Ubuntu) I got the same error.

carlo@acer17:~$ ping https://www.swi-prolog.org
ping: https://www.swi-prolog.org: Name or service not known

but is really strange is that if - in WSL - I launch swipl-win - built from source some time ago - i got

- pack_install(clpBNR).
% Contacting server at https://www.swi-prolog.org/pack/query ... ok
Install clpBNR@0.11.10 from GIT at https://github.com/ridgeworks/clpBNR.git Y/n?

Doesn’t seem very useful:

?- http_open('https://www.swi-prolog.org/',S,[]).
% http_open: Connecting to 'www.swi-prolog.org':443 ...
%       ok <stream>(000002295502d1c0) ---> <stream>(000002295502dd70)
6

ping takes a host, i.e., without https://

So, it seems your network is fine.

And that is where it ends? That is rather weird. It should continue with the handshake, e.g.

% http_open: Connecting to 'www.swi-prolog.org':443 ...
% 	ok <stream>(0x3513a900) ---> <stream>(0x3513aa00)
% > GET / HTTP/1.1
% > Host: www.swi-prolog.org
% > User-Agent: SWI-Prolog
% > Connection: close
% HTTP/1.1 200 OK
% Connection: close
% Content-Length: 3733
% Server: nginx/1.18.0 (Ubuntu)
...
S = <stream>(0x34f6e000).

Anyone else with similar problems (probably on Windows)? Which Prolog version?

7

Prolog version: (yesterday or so daily build)

Welcome to SWI-Prolog (threaded, 64 bits, version 9.3.16-12-g3c7f96a77)

Seems https hurts…

?- http_open('http://www.swi-prolog.org',S,[]).
% http_open: Connecting to 'www.swi-prolog.org':80 ...
%       ok <stream>(000002d13adb0910) ---> <stream>(000002d13adafe70)
% > GET / HTTP/1.1
% > Host: www.swi-prolog.org
% > User-Agent: SWI-Prolog
% > Connection: close
% HTTP/1.1 301 Moved Permanently

But I did a bit of a mess with ping, using different hosts. Now

In Windows

ping www.swi-prolog.org

Esecuzione di Ping dualstack.osff2.map.fastly.net [146.75.54.217] con 32 byte di dati:
Risposta da 146.75.54.217: byte=32 durata=40ms TTL=55
Risposta da 146.75.54.217: byte=32 durata=41ms TTL=55

ping swi-prolog.org

Esecuzione di Ping swi-prolog.org [194.164.198.54] con 32 byte di dati:
Risposta da 194.164.198.54: byte=32 durata=82ms TTL=48
Risposta da 194.164.198.54: byte=32 durata=93ms TTL=48

In WSL/Ubuntu

$ ping www.swi-prolog.org
PING dualstack.osff2.map.fastly.net (146.75.54.217) 56(84) bytes of data.
64 bytes from 146.75.54.217 (146.75.54.217): icmp_seq=1 ttl=54 time=66.7 ms
64 bytes from 146.75.54.217 (146.75.54.217): icmp_seq=2 ttl=54 time=73.2 ms```

$ ping swi-prolog.org
PING swi-prolog.org (194.164.198.54) 56(84) bytes of data.
64 bytes from ip194-164-198-54.pbiaas.com (194.164.198.54): icmp_seq=1 ttl=47 time=65.8 ms
64 bytes from ip194-164-198-54.pbiaas.com (194.164.198.54): icmp_seq=2 ttl=47 time=89.0 ms
8

It seems SSL_CTX_new(), creating a new SSL context simply hangs :frowning: Now the big question is why? Well, probably after updating OpenSSL … Normally, this would be spotted, but unfortunately the ssl test suite is disabled as it does not work in the docker build environment :frowning:

9

Could be the problem reported here ? I apply routinely every security upgrade M$ proposes, and most probably I haven’t accessed the packs repository from this early summer.
I don’t understand the answer, probably will be necessary to replace SSL_CTX_new() with SSL_CTX_new_ex()…

10

Thanks. I doubt this is the problem though as it hangs rather than retuning an error and the problem also happens when running swipl.exe on Linux under Wine.

11

Ok. I changed the build docker, replacing the OpenSSL dlls from Fedora 41 mingw-openssl with those from Win32/Win64 OpenSSL Installer for Windows - Shining Light Productions. That fixes the problem. Reported the issue at 2333301 – SSL_CTX_new() hangs in CRYPTO_THREAD_read_lock() Will make an announce

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