Bug#964902: libio-socket-ip-perl: AI_ADDRCONFIG breaks many test suites on IPv6-only hosts

Sat Jul 11 21:14:23 BST 2020

Package: libio-socket-ip-perl
Version: 0.39-2
Severity: serious
Tags: patch ipv6

This is a follow-up for #962047 "fails to build on IPv6-only buildds".

The background here is that a while ago new official build daemons were
added that only have IPv6 connectivity, and this exposed a new class
of build failures, mainly due to getaddrinfo(3) behaviour with the
AI_ADDRCONFIG flag.

Quoting Julien Cristau there:

> FWIW, it seems IO::Socket::IP passes AI_ADDRCONFIG to getaddrinfo, which
> then doesn't return ipv4 addresses because the host doesn't have
> non-local ones, even though the address we're trying to resolve is
> "127.0.0.1".
> 
> Passing either GetAddrInfoFlags => AI_NUMERICHOST or GetAddrInfoFlags =>
> 0 to both IO::Socket::IP->new calls in the test file lets it pass, by
> turning off the smarts in getaddrinfo.

We fixed the test suite of libio-socket-ip-perl itself in 0.39-2 by
making it pass AI_NUMERICHOST in all the tests. However, it turns out
that the problem is much more widespread than this.

I've been testing systematically for these issues by test rebuilding
the whole archive, and found

1) 138 packages that failed to build on a host with an IPv6 address
   on a "real" interface, and IPv4 + IPv6 on lo, but no internet
   connection

2) 8 of those 138 also failed to build on a host with both an IPv6 address
   and an IPv4 address on a "real interface", still without a real internet
   connection (these are regular "needs internet" bugs, not IPv6 specific)

3) only 42 of the remaining 130 packages fail to build with the same setup
   as 1), after applying the patch discussed below to IO::Socket::IP.

So it looks like the AI_ADDRCONFIG default of IO-Socket-IP is causing
88 potential build failures on the new IPv6-only buildds. Examples of
those can be seen on for instance

 https://buildd.debian.org/status/logs.php?pkg=libmojolicious-perl

 https://buildd.debian.org/status/logs.php?pkg=libtest-redisserver-perl

 https://buildd.debian.org/status/logs.php?pkg=libwww-mechanize-perl

The attached patch changes IO-Socket-IP to pass AI_NUMERICHOST to
getaddrinfo(3) when the address looks like an IPv4 numeric address (rather
than a hostname), and special cases a PeerHost value of "localhost"
not to use AI_ADDRCONFIG.

I have tried quite a few variants, and this was the best I could do
without removing AI_ADDRCONFIG (which is a documented feature) altogether.
(TODO: The patch does not currently update the documentation about the
new behaviour.)

It would be good to get something like this upstream of course, and it
will also need to go in src:perl which has a copy of IO::Socket::IP.

I've tested that this makes libio-socket-perl pass its own test suite
without the modifications in 0.39-2, so this supersedes the current test
suite patch.

Build logs can currently (but not guaranteed indefinitely) be found at

 http://perl.debian.net/rebuild-logs/sid-v6only/

 http://perl.debian.net/rebuild-logs/experimental-v6only/

where the latter had a patched libio-socket-ip-perl package pre-installed
in the chroot.

Below is the list of packages detected as fixed by this. I'll bring up the
other IPv6-related build failures on the debian-devel list soonish. Bugs
have already been filed for the handful of "needs internet" issues.

alice_0.19-2
boxbackup_0.13~~git20200326.g8e8b63c-1
gdnsd_2.4.2-1
kgb-bot_1.56-1
libanyevent-connection-perl_0.06-5
libanyevent-connector-perl_0.03-2
libanyevent-memcached-perl_0.08-1
libanyevent-redis-perl_0.24-2
libapache2-authcookie-perl_3.30-1
libapache2-reload-perl_0.13-3
libapache-authenhook-perl_2.00-04+pristine-7
libapache-singleton-perl_0.17-1
libapache-ssllookup-perl_2.00-04-3
libapp-termcast-perl_0.13-3
libaudio-mpd-perl_2.004-2
libcgi-application-plugin-captcha-perl_0.04-2
libcgi-application-server-perl_0.063-2
libcorona-perl_0.1004-4
libcpan-mini-inject-perl_0.35-1
libcrypt-ssleay-perl_0.73.06-1
libdancer-perl_1.3513+dfsg-1
libdanga-socket-perl_1.62-1
libfcgi-engine-perl_0.22-1
libfurl-perl_3.13-2
libgearman-client-perl_2.004.015-1
libhtml-html5-parser-perl_0.301-2
libhttp-async-perl_0.33-1
libhttp-daemon-ssl-perl_1.05-01-2
libhttp-server-simple-mason-perl_0.14-2
libio-socket-ssl-perl_2.067-1
libio-socket-timeout-perl_0.32-1
libjson-validator-perl_3.25+dfsg-1
liblwp-protocol-https-perl_6.07-2
libmime-tools-perl_5.509-1
libmojolicious-perl_8.56+dfsg-1
libmojolicious-plugin-assetpack-perl_2.08-2
libmojolicious-plugin-authentication-perl_1.33-1
libmojolicious-plugin-authorization-perl_1.0302-2
libmojolicious-plugin-basicauth-perl_0.08-1
libmojolicious-plugin-bcrypt-perl_0.14-2
libmojolicious-plugin-cgi-perl_0.40-1
libmojolicious-plugin-i18n-perl_1.60-1
libmojolicious-plugin-mailexception-perl_0.20-1
libmojolicious-plugin-renderfile-perl_0.12-4
libmojo-sqlite-perl_3.003-1
libmonitoring-livestatus-perl_0.80-1
libnanomsg-raw-perl_0.10-1
libnet-facebook-oauth2-perl_0.12-1
libnet-http-perl_6.19-1
libnet-https-nb-perl_0.15-1
libnet-ldap-server-test-perl_0.22-1
libnet-server-mail-perl_0.28-1
libnet-server-perl_2.009-2
libnet-sip-perl_0.822-1
libperlio-via-timeout-perl_0.32-1
libplack-app-proxy-perl_0.29-1
libplack-handler-anyevent-fcgi-perl_0.01-1
libplack-handler-fcgi-ev-perl_0.01-1
libplack-middleware-deflater-perl_0.12-2
libplack-middleware-session-perl_0.33-1
libplack-perl_1.0047-2
libplack-test-agent-perl_1.4-2
libplack-test-externalserver-perl_0.02-1
libpod-webserver-perl_3.11-1
libproc-guard-perl_0.07-1
libprotocol-http2-perl_1.10-1
libredis-fast-perl_0.26+dfsg-2
libredis-perl_1.9950-1
librest-client-perl_273-1
librpc-xml-perl_0.80-2
librt-client-rest-perl_0.60-1
libtest-fake-httpd-perl_0.08-1
libtest-http-server-simple-stashwarnings-perl_0.04-2
libtest-redisserver-perl_0.21-2
libtest-tcp-perl_2.22-1
libtest-www-declare-perl_0.02-4
libtest-www-mechanize-mojo-perl_0.0.20-1
libtest-www-mechanize-perl_1.52-1
libweb-id-perl_1.927-2
libweb-machine-perl_0.17-1
libwiki-toolkit-plugin-ping-perl_0.03-2
mod-gnutls_0.9.0-1.1
perlbal_1.80-3
pinto_0.14000-1
request-tracker4_4.4.4-1
starlet_0.31-1
starman_0.4015-1
twiggy_0.1025+dfsg-1

-- 
Niko Tyni   ntyni at debian.org
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