tests: quiet down commit graph

Newer versions of git enable the commit graph by default.
Since we blow away our temporary directories every test,
generating graphis is a waste and clutters stderr with
"Computing commit graph generation numbers" messages.

1 files changed, 2 insertions, 0 deletions

diff --git a/t/v2writable.t b/t/v2writable.t
index 7519b487..8bbcd45a 100644
--- a/t/v2writable.t
+++ b/t/v2writable.t
@@ -6,11 +6,13 @@ use Test::More;
 use PublicInbox::MIME;
 use PublicInbox::ContentId qw(content_digest);
 require './t/common.perl';
+use Cwd qw(abs_path);
 require_git(2.6);
 foreach my $mod (qw(DBD::SQLite Search::Xapian)) {
         eval "require $mod";
         plan skip_all => "$mod missing for nntpd.t" if $@;
 }
+local $ENV{HOME} = abs_path('t');
 use_ok 'PublicInbox::V2Writable';
 umask 007;
 my ($inboxdir, $for_destroy) = tmpdir();