Re: port conflicts when running tests concurrently on windows.

Hi,

On 2021-12-08 16:36:14 -0800, Andres Freund wrote:
> On 2021-12-08 14:45:50 -0800, Andres Freund wrote:
> > Is it perhaps time to to use unix sockets on windows by default
> > (i.e. PG_TEST_USE_UNIX_SOCKETS), at least when on a new enough windows?
>
> On its own PG_TEST_USE_UNIX_SOCKETS doesn't work at all on windows - it fails
> trying to use /tmp/ as a socket directory. Using PG_REGRESS_SOCK_DIR fixes
> that for PG_REGRESS. But the tap tests don't look at that :(.

The tap failures in turn are caused by the Cluster.pm choosing a socket
directory with backslashes. Those backslashes are then treated as an escape
character both by guc.c and libpq.

I think this can be addressed by something like

diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm
index 9467a199c8f..c2a8487bbab 100644
--- a/src/test/perl/PostgreSQL/Test/Cluster.pm
+++ b/src/test/perl/PostgreSQL/Test/Cluster.pm
@@ -119,7 +119,15 @@ INIT
$use_tcp = !$PostgreSQL::Test::Utils::use_unix_sockets;
$test_localhost = "127.0.0.1";
$last_host_assigned = 1;
- $test_pghost = $use_tcp ? $test_localhost : PostgreSQL::Test::Utils::tempdir_short;
+ if ($use_tcp)
+ {
+ $test_pghost = $test_localhost;
+ }
+ else
+ {
+ $test_pghost = PostgreSQL::Test::Utils::tempdir_short;
+ $test_pghost =~ s!\\!/!g if $PostgreSQL::Test::Utils::windows_os;
+ }
$ENV{PGHOST} = $test_pghost;
$ENV{PGDATABASE} = 'postgres';

I wonder if we need a host2unix() helper accompanying perl2host()? Seems nicer
than sprinkling s!\\!/!g if $PostgreSQL::Test::Utils::windows_os in a growing
number of places...

Greetings,

Andres Freund