tests: include error message when unable to create a FIFO

I have seen this message once or twice, but since the actual error
message was not included, I cannot definitely say what’s going on.

I think it might be a race condition where the file with the specified
tmpname() already exists, but let’s be sure before we attempt to fix it.

diff --git a/testcases/t/175-startup-notification.t b/testcases/t/175-startup-notification.t
index a85320ea84c8c4d7590ac0139878febb5bff8d81..9f0c046ab2dd0dd51d8cc62ff8adb780605df2e1 100644 (file)
--- a/testcases/t/175-startup-notification.t
+++ b/testcases/t/175-startup-notification.t
@@ -84,7 +84,7 @@ is_num_children($first_ws, 0, 'no containers on this workspace yet');
 # echo its $DESKTOP_STARTUP_ID. We (blockingly) read the variable into
 # $startup_id in the testcase.
 my $tmp = tmpnam();
-mkfifo($tmp, 0600) or BAIL_OUT "Could not create FIFO in $tmp";
+mkfifo($tmp, 0600) or BAIL_OUT "Could not create FIFO in $tmp: $!";
 
 cmd qq|exec echo \$DESKTOP_STARTUP_ID >$tmp|;